Suggestions for a EL84 amp?

[diamondsouled]

Been thinking about finding a use for those Mullard 7189s and not being all that familiar with amps using them would appreciate some help narrowing down the field.

Since this will be for a smaller system I'm thinking integrated would be preferable but am willing to go with separate components.

My list keeps growing but like I said I have no personal, ears on, experience with EL84 amps so please chime in.

Seems the Eico HF81 has a good rep for a integrated EL84 amp, as well as the Dynaco ST35, Scott 299A A and B, and the Pilot 240.

What are people's faves out of these fine examples or others not listed? Are there any new EL84 amps worth serious consideration that won't break the bank? Kit form would be fine.

If someone happens to have an extra one of the aboves around or something else EL84 PM me please.

Cheers

Lar

[mhardy6647]

I have yet to hear a bad sounding EL84 amp, SE or PP; hope that helps!

[diamondsouled]

I have yet to hear a bad sounding EL84 amp, SE or PP; hope that helps!

That's kind of the impression I have been getting in the little bit of research I've been doing, lol. Kind of makes narrowing the field down a bit challenging; hey, but that's half the fun!:banana:

Received a message recently about a EL84 amp shootout that has some interesting and useful info:

We haven't had any tube amp party for quite a while but last Friday I
attended a great EL84 PP amp shoot-out in John Keung's world-famous
LS3/5A/Vinatge Leak hifi den.

The 4 amp we tested are :
Leak TL12+
Stern Mullard 5-10
Klangfilm V410
TAB V81

Playing at the home ground is John's pair(s) of Leak TL12+ (yes, he
got 4 units) and I brough my pair of Stern Mullard 5-10 (with
Partridge power transformers) to join the England Team.

The challengers are the Klangfilm V410 and TAB V81 from the old West
Germany.

All 4 amps are EL84 PP producing around 10W-12W power and these 4 are
the best sounding of such type of amp I ever heard.

The system consisted of :
Source - Denon CD transport/Audio Note Zero DAC
Pre-amp - Fisher 400CX-2
Speakers - Chartwell LS3/5A 15 ohm

As expected, all 4 amp sound quite different from each other. The
Leak sounded the most sweet and seductive with just what you expected
from the EL84 tubes. By comparison, the Stern has not as much the
high extension but got more bass and a deeper sound stage. Overall,
more MSG and more soothing as well.

The V410 is completely different from the 2 England representatives.
It actually does not sound like a EL84 amp at all! If blindfolded,
one would probably think it was a 25W EL34 PP amp playing instead.
There are just so much more frequency extension at both ends, more
punch and transistency. It asserted authority over music unlike any
EL84 pp amp out there.

The TAB V81 turned out to be out-of-form and gave a pretty lackluster
performance. I believe the reason is because of the incompatibliity
with the sing-ended output of the FIsher 400CX-2. I drove the V81
again yesterday with the matching TFK V72 and it was like night-and-
day. Again, it shows that the TFK/TAB/Siemens/Maihak V-series studio
power amp like the V73 and V69 can only sound right with balanced
output from the matching V-series studio pre-amp.

Overall, I think the score for England vs. West Germany is a 2-2 draw
but the player of the day has to be the V410.

-------------

Cheers

Lar

[grateful]

The scott is the nicest of the group. The EL84 model is the 222.

[ashok]

Many on AK, including myself, have built the DIYTube ST-35 amplifier. I built it in early 2004, and it has been working flawlessly since then. It is capable of 17W or so per channel. I run it in triode mode, with maybe 8W per channel. The tube complement is a 5751 as the driver, a 12BH7 as the phase splitter, and Russian 6p14p-ev power tubes. Very sweet sounding amplifier.

You can buy the PCB from Shannon Parks - please check out DIY Tube (www.diytube.com).

Dynakit Parts (http://www.dynakitparts.com/store/product.aspx?id=1) offers complete kits. But the board is not the diytube board.

Hope this helps.

Ashok

[mhardy6647]

I am a bit... biased, myself.

http://img.photobucket.com/albums/v223/mhardy6647/P1020749.jpg
http://img.photobucket.com/albums/v223/mhardy6647/openvalencia.jpg

[Tom Bavis]

Triode Electronics sells the DIYtube kit.

[analog addict]

Triode Electronics sells the DIYtube kit.

Is that really you? No comment about some of the SC EL84 amps?....:saywhat:

I've had a number of vintage EL84 based amps, and the SC ASR-433 is a wonderful sounding integrated amp. The 333 is also very nice. I've also enjoyed a Magnavox 9302 power amp, which Cableguy recently pried out of my hands....:tears:

The nice thing about a vintage amp is that many of them have schematics available, and (hopefully) don't require rounding up a set of transformers, chassis, etc. Rework/restore one to learn the ropes a bit, then tackle a ground up build project....:thmbsp:

[dividebytube]

The Heath UA-1 and UA-2 are good monoblocks to look for. Also the Fisher SA100 and SA-16.

I owned a pair of UA-2 and the output iron on them is massive for a 15W amplifier. I actually squeezed a choke in underneath, along with a pair of Solen capacitors.

[Urizen]

Some of the older Sherwood gear is said to sound really nice, along with good build quality. I'm not that familiar with their tube line-up. Hopefully someone with more knowledge will chime in. I'll second AA's recommendation for the little Magnavox amps and their ilk.

I have been really happy with my Almarro A205A. At 5 WPC and being SEP, higher efficiency speakers work best. However, I've used it with 90dB speakers with good results at low volumes and in a smaller room. Through La Scalas, it's got plenty of headroom, is dead quiet, and sounds great to my ears.

They've gotten pricey lately (made in Japan), but if you can find a used one at a reasonable price, by all means give it an audition.

[mhardy6647]

Soem of the Sherwoods used 7189s, some 7591s, and some 7868s :-)

[Urizen]

Soem of the Sherwoods used 7189s, some 7591s, and some 7868s :-)

No EL-84 amps? Oh, well.:withstpd:

[Tom Bavis]

Is that really you? No comment about some of the SC EL84 amps?....:saywhat:



Well... I actually haven't heard an ASR-333 or 433 in quite a while - I had one but sold it around 1975... (damn - showing my age!) but I picked up the set of iron from a mangled one, and it's destined to become an amp one day soon...

[Tube Radio]

Find you a Magnavox 6BQ5 stereo amp.

[mhardy6647]

7189 is basically a robust EL84.

[imready]

My Pilot 903b's sound pretty good!

[jon_s]

I would definitely suggest a Sherwood S-5000. I have one that I just haven't gotten around to restoring yet. Very nice build quality, and still somewhat affordable.

[diamondsouled]

Thanks for all the suggestions! I did come across the ST-35 kit and it looks quite interesting. The Sherwoods were something I hadn't considered. Apparently it is the original S-5000 that has the EL84 and after they went to the 7591.

Will keep an eye out for the Maggies as well.

Thanks

Lar

[clydeselsor]

Well... I actually haven't heard an ASR-333 or 433 in quite a while - I had one but sold it around 1975... (damn - showing my age!) but I picked up the set of iron from a mangled one, and it's destined to become an amp one day soon...

I owned a Stromberg-Carlson ASR-333 from 1977 until 1984. It is a great sounding "east coast sound" type of amp. I should have never sold it!!

[cableguy]

I have several favorites....
Analog Addicts SC 433 is very sweet (and formerly mine..:tears:)
and this Maggie 6bq5 formerly AA's :scratch2:
I've also enjoyed a Magnavox 9302 power amp, which Cableguy recently pried out of my hands....

http://inlinethumb24.webshots.com/41623/2329366180103324012S600x600Q85.jpg (http://good-times.webshots.com/photo/2329366180103324012tTjMSK)

Look any different Alan????

Like mhardy6647 I have yet to run across one of these amps that I didn't favor....:yes:



Bill

[Bruce221]

Leak geer is prime -the HF81 would be a good to better choice over the dynaco sca 35-just my opinion-and the tube amp party well listening with some champagne wow wowwweee .

[mhardy6647]

I am in the process of procuring an SCA-35, but I've yet to A/B the two above-mentioned integrated amps. I can say that the Dyna stereo power amp version, called the ST-35 is a very nice little amplifier and something of a sleeper. Unfortunately, they are not common at all. www.dynakitparts.com is selling a new version of the ST-35, though. This would be well worth consideration, IMNSHO.

http://www.dynakitparts.com/store/images/productimages/zoom/51C.gif

[analog addict]

I have several favorites....
Analog Addicts SC 433 is very sweet (and formerly mine..:tears:)
and this Maggie 6bq5 formerly AA's :scratch2:


http://inlinethumb24.webshots.com/41623/2329366180103324012S600x600Q85.jpg (http://good-times.webshots.com/photo/2329366180103324012tTjMSK)

Look any different Alan????

Like mhardy6647 I have yet to run across one of these amps that I didn't favor....:yes:



Bill

Bill,
What happened to it's clothes??? I guess you always did like 'em nekkid....:D Are you getting the outfit "tailored" ?

I'm kinda regretting selling it now, 'cause it looks like the 433 has some distortion in one channel along with reduced gain/volume...:tears: (Anyone have any ideas?)

[SET12]

Been thinking about finding a use for those Mullard 7189s and not being all that familiar with amps using them would appreciate some help narrowing down the field.

Since this will be for a smaller system I'm thinking integrated would be preferable but am willing to go with separate components.

My list keeps growing but like I said I have no personal, ears on, experience with EL84 amps so please chime in.

Seems the Eico HF81 has a good rep for a integrated EL84 amp, as well as the Dynaco ST35, Scott 299A A and B, and the Pilot 240.

What are people's faves out of these fine examples or others not listed? Are there any new EL84 amps worth serious consideration that won't break the bank? Kit form would be fine.

If someone happens to have an extra one of the aboves around or something else EL84 PM me please.

Cheers

Lar

How about this one!

Its a pilot power amp circuit from an integrated amp that was in need of major restoration. My friend asked what can we do! So I bypassed all the circuitry that I thought was garbage meaning the entire front end and came up with this simple power amp that has about 6db of negative feedback for some nice body to the music and also it has about a 450mv input sensitivity for 20 watts out. We ended up using a GZ37 rectifier tube for the amps best sonics it also was constructed with carbon resistors. I did a new layout of the circuitry which produced an even quieter circuit from the original. We also added enough capacitance to run the output stage right of the cap that the rectifier tube was feeding to give the amp some real punch! The typical 100 ohm resistors that are in many early EL84 circuits just suck the life right out of these great sounding amplifiers IMO and I might say its a pretty strong one. We also used the original Iron and spray painted the iron with piano gloss black. The brass top plate of this amp was custom cut at a local metal shop at a reasonable price and my friend then hand rubbed the brass to a mirror finish. The speaker binding post are Edison Price mounted on a strip of brass with a good quality RCA jack. The wood skirt is walnut and a bottom cover is a sheet of copper sprayed black. My friend owns Dunlevy 4's and this amp drove them to some of the most amazing EL84 sound that I have ever heard. Making me comment "No wonder why the EL84 is so legendary"

http://img514.imageshack.us/img514/9755/el84powerampfk1.jpg

[mpholland]

Hey SET12, can you send me a little more info on how you went about building that amp? I have a Pilot 602 that needs a major overhaul and I think your "cure" might be a little more to my liking.

[SET12]

Hey SET12, can you send me a little more info on how you went about building that amp? I have a Pilot 602 that needs a major overhaul and I think your "cure" might be a little more to my liking.

Sure, Right now I have to get some shut eye as I work nights! Can you send me a schematic that I might take a look at it?

I'm rather fond of Pilots

I found a 602 on ebay

Item number: 320247455694

SET12

[paul cbc]

I really like my little Fisher X-100 Integrated amplifier.

It's a bit confusing as there were lots of iterations:

See Post #5 for a nice rundown on the various X-100 units:
http://audiokarma.org/forums/showthread.php?t=42433&highlight=fisher+x-100

This thread has a nice picture of the type X-100 that I have:
http://www.audiokarma.org/forums/showthread.php?t=142283&highlight=fisher+x-100



Lots of nice options to put those Mullards to use. :thmbsp:
Paul

[diamondsouled]

"Lots of nice options to put those Mullards to use."

Exactly my thought Paul.

I've been kinda wondering why I haven't seen a EL84 amp yet with 6SN7s instead of 12AX7s etc.. Any reason a person couldn't pair these two tubes up for a EL84 integrated?

I would think that using an octal splitter and driver tube along with a nine pin power tube might yield some interesting aesthetic design possibilities. That and a nice tube rectifier.

Cheers

Lar

[Celt]

I am in the process of procuring an SCA-35, but I've yet to A/B the two above-mentioned integrated amps. I can say that the Dyna stereo power amp version, called the ST-35 is a very nice little amplifier and something of a sleeper. Unfortunately, they are not common at all. www.dynakitparts.com is selling a new version of the ST-35, though. This would be well worth consideration, IMNSHO.


RichPA and I both have built the Dynakit ST-35's. I built mine "old school" with parts that would have come with the 1963 model and as I recall, Rich went the upgrade path with his. The two builds can be found here:
http://www.audiokarma.org/forums/showthread.php?t=70237

[imready]

Cool, a tube amp integrated into washing machine. I bet the neigbors get pissed when you have it on the "agitation" cycle. :banana:
I have several favorites....
Analog Addicts SC 433 is very sweet (and formerly mine..:tears:)
and this Maggie 6bq5 formerly AA's :scratch2:


http://inlinethumb24.webshots.com/41623/2329366180103324012S600x600Q85.jpg (http://good-times.webshots.com/photo/2329366180103324012tTjMSK)

Look any different Alan????

Like mhardy6647 I have yet to run across one of these amps that I didn't favor....:yes:



Bill

[Bruce221]

Diamoundsould-If you want 6sn7 front end which would be the big brouthe r to the 12au7(larger sound stage and depth to the music go for the eico hf87 or the hf89-the hf89 is harder to find due to less production-Both I rate as A-1 however they both use EL34s.

[SET12]

How about this one!

Its a pilot power amp circuit from an integrated amp that was in need of major restoration. My friend asked what can we do! So I bypassed all the circuitry that I thought was garbage meaning the entire front end and came up with this simple power amp that has about 6db of negative feedback for some nice body to the music and also it has about a 450mv input sensitivity for 20 watts out. We ended up using a GZ37 rectifier tube for the amps best sonics it also was constructed with carbon resistors. I did a new layout of the circuitry which produced an even quieter circuit from the original. We also added enough capacitance to run the output stage right of the cap that the rectifier tube was feeding to give the amp some real punch! The typical 100 ohm resistors that are in many early EL84 circuits just suck the life right out of these great sounding amplifiers IMO and I might say its a pretty strong one. We also used the original Iron and spray painted the iron with piano gloss black. The brass top plate of this amp was custom cut at a local metal shop at a reasonable price and my friend then hand rubbed the brass to a mirror finish. The speaker binding post are Edison Price mounted on a strip of brass with a good quality RCA jack. The wood skirt is walnut and a bottom cover is a sheet of copper sprayed black. My friend owns Dunlevy 4's and this amp drove them to some of the most amazing EL84 sound that I have ever heard. Making me comment "No wonder why the EL84 is so legendary"

http://img514.imageshack.us/img514/9755/el84powerampfk1.jpg

Heres the schematic for it but as I said I modified its supply for a more dynamic presentation.

88864

[Marantz 500]

Over the years I've had two Dynaco SCA-35, and it does have a very special sound. I sold both when I got a Dynaco ST-70, which is a great amp, but I actually think the SCA-35 amps sounded better in some ways. Not a lot of power though, so one needs to use efficient speakers.

Recently got hold of a Dynaco Stereo 35 which I have only hooked up once, but it seemed to have that wonderful tone I remember from my SCA-35's. I bought Quad II monoblocks at the same time, and I have always been curious about these, so I am trying them out first. But judging from first impressions I'm not so sure the Quad II's actually sound better than the Dynaco ST-35. The Quad's LOOK a lot better, though...

http://msnbcmedia.msn.com/j/msnbc/Components/Photos/060508/techColumn/ST-35.standard.jpg

http://www.hi-fiworld.co.uk/hfw/hfwImages/oldeworlde/quad2amp.gif

(Both SCA-35 and ST-35 use EL84 output tubes, of course.)

[mpholland]

Am on the lookout for a 602M SAMS at this time. None on the Bay. Might try library. Any chance you can change the res on your scan? Pretty tiny on my screen. I figure if the trannies and the tubes are the same, should be able to achieve similar results with a little help.

[SET12]

Am on the lookout for a 602M SAMS at this time. None on the Bay. Might try library. Any chance you can change the res on your scan? Pretty tiny on my screen. I figure if the trannies and the tubes are the same, should be able to achieve similar results with a little help.

This should do it! If not try importing it into your pictures and then enlarging it. Other wise I'll try again. I'm sure you'll have some questions and I'll be glad to answer them. Feedback is off the 8 ohm tap. The phase inverter is called a Paraphase inverter its in the RCA tube manual. I have other EL84 circuits that may even be better but this is a Pilot and the best version IMO.
89824

89825

SET12

[mpholland]

Thanks for the artwork...much better this time. Will give me something to look at until I get a schematic for my 602M. I will have to check on similarities between voltages, resistances and such. I am not in a big hurry so don't be surprised to just hear from me some day out of the blue. I work a LOT and am not the most social of people. Not to mention some other projects such as the Craftsman 500 and a couple of speaker projects. Oh yeah, can't forget the old Meissner 9-1093 6L6. Have the whole kit, but thinking of scrapping the tuner. Thanks, and will keep in touch.

[Dr Tinear]

I have a Dynaco SCA-35 and a Sherwood S-5000 (the original EL-84 model from 1958, not the later model that used 7591s). The Sherwood sounds much better to me than the Dyna -- punchier and more extended in the bass and more detailed in the mids and highs.

[diamondsouled]

Thanks to all here for the feedback. I'm much more knowledgeable for it.

Think I'll go with a TEAD Linear A EL84 amp:

http://tomevansaudiodesign-usa.com/_wsn/page4.html

Just kidding, haven't won the lottery yet!

Wanting a amp with a rectifier tube as well as headphone plug is helping to narrow the field down a bit.

Having fun that's for sure. Never realized that the EL84 is so revered as an audio tube. Speakers needing lots of power kind of put it into the back ground for a while but it sure has made a come back!

Can't wait till I find what I'm looking for and actually get to hear em!

If I can find an affordable Almarro A205A MkII I might go for one of those.

Cheers

Lar

[WhiteSE]

i am surprised no one suggested a Pilot SA-232...

[diamondsouled]

i am surprised no one suggested a Pilot SA-232...

It's on my not so short short list, lol!

Cheers

Lar

[Tungsol]

Here is another for your short list....

Audio Note OTO SE.

Integrated EL84 Single Ended 10W

Its not too expensive on the used market. The phono model I recently acquired is built like a tank and mates quite well with my JBL C-38s.

[zekk]

Hey WhiteSE! I'm with you.
My Pilot SA-232 is sweet and it occasionally put my MC-30 to backstage!
Speaker is Altec 604-E with a 101dB.

Cheers!

[WhiteSE]

Hey WhiteSE! I'm with you.
My Pilot SA-232 is sweet and it occasionally put my MC-30 to backstage!
Speaker is Altec 604-E with a 101dB.

Cheers!

did you post a pic of that setup??

[boyo]

The original Sherwood 5000 is truly a special unit.

[zekk]

Sorry, not yet!
Still struggling with my image posting.

[SET12]

Thanks to all here for the feedback. I'm much more knowledgeable for it.

Think I'll go with a TEAD Linear A EL84 amp:

http://tomevansaudiodesign-usa.com/_wsn/page4.html

Just kidding, haven't won the lottery yet!

Wanting a amp with a rectifier tube as well as headphone plug is helping to narrow the field down a bit.

Having fun that's for sure. Never realized that the EL84 is so revered as an audio tube. Speakers needing lots of power kind of put it into the back ground for a while but it sure has made a come back!

Can't wait till I find what I'm looking for and actually get to hear em!

If I can find an affordable Almarro A205A MkII I might go for one of those.

Cheers

Lar

:scratch2: I actually thought of a similar design some 10 yrs ago. I understand the topology. You could build one of these Ultra linear SET amps all tube based with perhaps a C4S current source front end for very low distortion, Its a very dynamic design! Which was designed to compete with large Triodes and to be similarly low in distortion as a PP amp. You can also have a headphone jack as well.

If you have an interest in trying to build one of these PM me.:smoke:

[mqracing]

How about this one!

http://img514.imageshack.us/img514/9755/el84powerampfk1.jpg



Hi. Beautiful amp. Just gorgeous. Two quick questions.

1) you mentioned that the input sensitivity was very low (I should have copied the value)--- do you use an active preamp? Is it (the amp) too sensitive--- that your volume control becomes a "hair trigger"?

2) you mentioned that your friend polished the top plate--- and it looks great---- did he then shoot it with a clear coat?

nice job.

MSL

[analog]

I am listening to an Sonic Frontiers Anthem Interated PPP EL84 as I type this, has the EL84 sound with more punch. Ihave enjoyed this amp for a few years now.

[SET12]

Hi. Beautiful amp. Just gorgeous. Two quick questions.

1) you mentioned that the input sensitivity was very low (I should have copied the value)--- do you use an active preamp? Is it (the amp) too sensitive--- that your volume control becomes a "hair trigger"?

2) you mentioned that your friend polished the top plate--- and it looks great---- did he then shoot it with a clear coat?

nice job.

MSL

Thank you!

My friend Don uses a First Sound, Presence Preamplifier with 15db of gain I also might add its the single most awesome Preamplifier that I have ever heard! Don uses a Rotel CD player model of which I don't recall the model and Dunlevy 4 speakers. I haven't been to his home in the last couple of yrs but I seem to remember his volume control being mostly 10-11 o,clock I don't remember where his starts though.

With my Motiff preamplifier which is 10 db of gain, the input is attenuated 85% at 12 o'clock, the control runs from 6-4 o'clock. With its Audio Tapper Volume control at this setting its at just 12kohms out of 80k that leaves the preamps output at 1/2 of unity gain on the Motiff .

Based on a little math not accounting for any losses the amp is around 30db of gain and at 20 watts thats around a 400mv input sensitivity which he really likes.

As for a hair trigger I seem to remember an Dennis Had modifying his AE 300B amp in a Sound Practices Magazine article for a guy that wanted to run his CD direct and if I remember Dennis set the gain for 130mv for 7 watts out doing this I believe Dennis commented that the amp was "Explosive" in its dynamics and I would guess so! But not at the 4-500mv level but I don't think I'd go any lower if using a preamplifier and in my system now I'm at 1-2 o'clock on a Sony X77ES for any degree of audible clipping with my 10 watt SET with about 500mv input sensitivity for 10 watts out 98db/watt efficient speakers.

In my own system I don't run a preamp because I can't afford the Presence preamp and haven't got around to designing one and I seriously doubt I'll be able to come close to the Presence. So I use CD direct as most line stages just get in the way for me.

The Plate does not have a clear coat on it.

And BTW I want to thank you for the nice article that you had in Sound Practices Magazine yrs ago on transformer theory as it gave me a real working understanding of Output Transformers in my amp design work.

And Thanks Again!

SET12

For the DIYer I recently bought the CD archive off of Ebay for 29.95$ from Joe Roberts of all the Sound Practices Issues IMO they are worth their weight in gold!

[mqracing]

The Plate does not have a clear coat on it.

And BTW I want to thank you for the nice article that you had in Sound Practices Magazine yrs ago on transformer theory as it gave me a real working understanding of Output Transformers in my amp design work.




Thanks for your detailed response. I, too, have heard good things said about the First Sound preamp products.

Dennis Had--- what a hoot to party with--- we had a lot of fun years ago at the Philadelphia Single Ended Symposium. And his big Benz could haul the mail down the surekill expressway in philly. My lil ole alfa had it's tongue hanging out !!!

I like copper top plates--- both for looks and for function---
I wonder if his copper still looks as good as it does in the picture some time later without any protective coatings.

Your mention of Sound Practices--- Joe is a philly boy originally--- south philly. The first single ended airgapped output we ever designed from scratch was at Joe's promptings and included in the SP #1 article on building a Model 91 amp. All of his mags were top notch. But the net has killed off all but the most robust print rags.

And thanks for the compliment on the articles I wrote for Joe. I had fun doing them--- as I too was at that time an early student of magnetics.

MSL

[mhardy6647]

Whoa, Mikey!?! Welcome, glad to see you here!

[Tube Radio]

Most of those Magnavox amps can be found for little $$$. IIRC I found my Magnavox in a console labeled Columbia. $14.00 for the amp, record changer & two speaker cabinets one which had the electronics in it. If you do find a Magnavox EL84 amp depending on which amp you find it may be advisable to install better quality outout transformers to help the low bass out a bit. IIRC my Magnavox SEP 6BQ5 stereo amp sounded ok stock. When I installed better output transformers the sound improved. Now it is used only with my computer for playung games and sometimes watching movies since I have a Scott LK-72A in my main system.

[SET12]

Most of those Magnavox amps can be found for little $$$. IIRC I found my Magnavox in a console labeled Columbia. $14.00 for the amp, record changer & two speaker cabinets one which had the electronics in it. If you do find a Magnavox EL84 amp depending on which amp you find it may be advisable to install better quality outout transformers to help the low bass out a bit. IIRC my Magnavox SEP 6BQ5 stereo amp sounded ok stock. When I installed better output transformers the sound improved. Now it is used only with my computer for playung games and sometimes watching movies since I have a Scott LK-72A in my main system.

Yes, I've done the same!:yes: I agree I would call it a substantial improvement!:thmbsp:

[SET12]

I am listening to an Sonic Frontiers Anthem Interated PPP EL84 as I type this, has the EL84 sound with more punch. Ihave enjoyed this amp for a few years now.

No doubt in my mind!:music: Which is why I designed this PPP based on the above fave Pilot circuit I used above. This one is with dual 5AR4 rectifiers and Voltage regulator tubes for the screens with a One Electron Power transformer and Hammond Outputs for a good friend of mine.

http://img152.imageshack.us/img152/7813/50wattel84powerampfe5.jpg

I find that PPP EL84's are very competitive with EL34 and 6550 PP amplifiers.

SET12

[mqracing]

I find that PPP EL84's are very competitive with EL34 and 6550 PP amplifiers.



I think EL-84's are a good choice. Easy to get current production at reasonably good prices. There are the russian equivalents--- which I just got a handful of for like four bucks each. And if you enjoy the vintage stuff--- still a lot of American made EL-84's out there. And this tube sounds good.

other advantage I see is that a PPP config--- the Dyna ST-70 output (4300 ohms CT) listed EL-84 PP para pairs as an app for this trans.

With your example/suggestion it would be easy for folks to source the various hardware from a wide range of both new and vintage sources (i.e., take offs from existing amps for example).

And in my opinion we should be looking at circuits and topologies which would expand the iron choices for diy builders not limit their choices by selecting an idiosyncratic circuit topology which could only be met by using just one or two "handpicked by someone else" sources for the hardware.

MSL

[mqracing]

Whoa, Mikey!?! Welcome, glad to see you here!

Thanks Mark.

[zenith2134]

SET12--thats an impressive design. Alls I know is that the Stromberger Carlson ASR433 is one hell of an el84 amp. It sounds stronger than it should and it still sings in the mid's like an el84 should. Incredible bargain too.

The new sensor Mullard reissues are darn good too, thats what mine runs :thmbsp:

[goraman]

I would have to lobby for the Manley Labs Sting ray and like that you can choose from triode or ultra liner and it has a master bias ajustment so you can run any EL84 you choose and the trim pots on top allow you to bias in up to 10 mv with ease. An it sounds wonderful I find the best combo is 1950 RCA black plate 12AT7's 1464 Ratheons and the new TAD EL84STR's.It really needs to be retubed to bring out it's true sound the russian military tubes it comes with are detailed but very hard sounding compaired to any other tube you might choose.I rolled several octets of El84's and the Tads where the clear winners even compaired with menny NOS. The Tads are the best new tube a very nice copie of the 1950's RCA super large plate,they improved it even further by useing gold screen wire and makeing the anode larger and stronger.The glass ismuch thicker too.They have a raised midrange,and in triode the bass dosent shrival up into a little tapping sound like so menny other el84's and they are not bass shy like most 84's highs are nice and warm unlike the ear splitting JJ's.

[SET12]

Sorry! Editing mess up!

[SET12]

And in my opinion we should be looking at circuits and topologies which would expand the iron choices for diy builders not limit their choices by selecting an idiosyncratic circuit topology which could only be met by using just one or two "handpicked by someone else" sources for the hardware.
MSL

I'm all for new ideas certainly one has a lot of choices with Iron for instance I see EL84's running PP with Primary's running from 6.6k to as high as 10k or a 300B circuit from 2.5 k to 5k or your Para feed Iron which I haven't heard yet but look forward to it.

I'm also looking forward to using Grid Iron soon!

As for the classical designs I enjoy them! But none of my work takes the classical approach.

I use LED's for biasing, Current Sources for Plate loading,Large power supplies that are fast and transparent. I accidentally discovered a method of using massive amounts electrolytics and then using Polypropylenes retaining the full Polypropylene transparency without the electrolytic sound signature. It may be patentable as I have never seen an application of power supplies like I build them. I just haven't looked into it. But they really work for me!

I'd also like to thank you Mike for the gentlemen like way you discuss things! Its a real pleasure! :yes: :smoke:

SET12--thats an impressive design. Alls I know is that the Stromberger Carlson ASR433 is one hell of an el84 amp. It sounds stronger than it should and it still sings in the mid's like an el84 should. Incredible bargain too.

The new sensor Mullard reissues are darn good too, thats what mine runs :thmbsp:
Thanks much! I'll pass the word to my buddy! And I'll bet its not an Ultra Linear design! As I find the Pentode connected circuits more dynamic myself of course theres a trade off and thats a bit more distortion. But I'll take the Pentode connection myself!
I love Mullards I'll have to check into them! Thanks Again!

I would have to lobby for the Manley Labs Sting ray and like that you can choose from triode or ultra liner and it has a mater bias ajustment so you can run any EL84 you choose and the trim pots on top allow you to bias in up to 10 mv with ease. An it sounds wonderful I find the best combo is 1950 RCA black plate 12AT7's 1464 Ratheons and the new TAD EL84STR's. I've heard the stingray many times and the Mahi's wonderful amps indeed!

SET12

[mhardy6647]

Then there is the 'poor person's Stingray'; the "Classic 50/50" push-pull parallel stereo MI/PA amp from Peavey :-)

http://img.photobucket.com/albums/v223/mhardy6647/P1020121.jpg
http://img.photobucket.com/albums/v223/mhardy6647/PeaveyClassic5050topless.jpg

The tips of the top quad of a total of eight horizontally-mounted EL84s are barely visible in the center of the amp towards the back.

[SET12]

Do you have a schematic for it?

[zenith2134]

Good question about the ultralinear. I don't think the asr-433 is UL.