ST-70 or 120 kit build opinons?

[HiFiThor]

I have been giving some thought to trying a kit build of these amps. Dynaco has kits and tubes4hifi also has kits. I'd be interested in hearing from anyone out there who has gone down this path and after living with it for awhile what would they recommend?

I will be using Magnepan speakers but I can also use Dhalquist DQ-10's or Shihininian Obelisks. I like light classical as well as rock.

 

[sKiZo]

Big fan of the Latino ST120 here. It's got plenty of reserve power to drive a quad of KT120's. Been listening to mine for about four years now with nary a regret.

Driving a pair of 85db McIntosh XR16's using bass synth and expansion, listening to most anything, but with a LOT of prog rock. No issues pushing Porcupine Tree to sternum shattering levels if I've a mind to. Incredible dynamics with classical as well, with super dark quiet and instant response on the crescendo ...

PS ... if you want to use KT88's or KT120's, those will push a 5AR4 rectifier hard. I strongly suggest you go with a solid state rectifier (Weber WZ68 copper cap is a popular plug in option) or a GZ37/GZ33.

 

[HiFiThor]

Big fan of the Latino ST120 here. It's got plenty of reserve power to drive a quad of KT120's. Been listening to mine for about four years now with nary a regret.

Driving a pair of 85db McIntosh XR16's using bass synth and expansion, listening to most anything, but with a LOT of prog rock. No issues pushing Porcupine Tree to sternum shattering levels if I've a mind to. Incredible dynamics with classical as well, with super dark quiet and instant response on the crescendo ...

PS ... if you want to use KT88's or KT120's, those will push a 5AR4 rectifier hard. I strongly suggest you go with a solid state rectifier (Weber WZ68 copper cap is a popular plug in option) or a GZ37/GZ33.

Thank you for your input. I have been a high power SS fan almost all my life and just want to see what's up with tubes. I was thinking of mono blocking the ST -120s. Sounds a little crazy when one will do I think.

I have seen tube power amps for sale but no so much tube preamps. I basically will only use with my TT but having an AUX input is OK too. Any suggestions?

 

[sKiZo]

I use a Sansui QRX 9001 receiver, so someone else can chime in on pre recommendations. If you do decide to go with monoblocks, the Latino M-125's get rave reviews. That said, one of the big factors in having extra power is to avoid clipping, but ... tube watts are virtually bigger than SS watts there. An SS clip tends to be quite harsh ... speaker breaking harsh, while a tube amp "soft clips" with maybe a bit of a thud or distortion. I replaced a McIntosh MC2205 with the Latino ST120, and the same SPLs that would blow speaker fuses and make heart stopping crunchy noises with the Big Mac are hardly noticeable now. Did the same internal discussion on options when I was looking, and can't say I have any regrets.

Oh. If you've a receiver that has a PRE OUT loop, then you're good to go. My Sansui doesn't have that - I run the Latino off a tape loop. That bypasses the tone and volume controls on the receiver, but no worries here, as I take care of all that with EQ and dual volume controls on the amp itself, as well as software line level controls in the chain. That's another thread though, so forget I mentioned it. ;-}

 

[gadget73]

At the ST-120 power level, I'd go Mark III monoblocks instead. Less hernia inducing. Big tube stereo amps are unpleasant to move.

 

[HiFiThor]

I use a Sansui QRX 9001 receiver, so someone else can chime in on pre recommendations. If you do decide to go with monoblocks, the Latino M-125's get rave reviews. That said, one of the big factors in having extra power is to avoid clipping, but ... tube watts are virtually bigger than SS watts there. An SS clip tends to be quite harsh ... speaker breaking harsh, while a tube amp "soft clips" with maybe a bit of a thud or distortion. I replaced a McIntosh MC2205 with the Latino ST120, and the same SPLs that would blow speaker fuses and make heart stopping crunchy noises with the Big Mac are hardly noticeable now. Did the same internal discussion on options when I was looking, and can't say I have any regrets.

Oh. If you've a receiver that has a PRE OUT loop, then you're good to go. My Sansui doesn't have that - I run the Latino off a tape loop. That bypasses the tone and volume controls on the receiver, but no worries here, as I take care of all that with EQ and dual volume controls on the amp itself, as well as software line level controls in the chain. That's another thread though, so forget I mentioned it. ;-}

My Pioneer Spec-1 Pre-amp could do the job, it has the capacity to totally bypass the tone controls, still it's a SS device. I'd like to put together from a kit a tube only pre-amp, keep things a minimal as possible. Most of what I have seen are hybrids and have some SS devices in the signal path. Am I missing something?

 

[vaathi]

skizo.. Weber suggest W1 for use in hifi.
https://www.tedweber.com/ws1

 

[sKiZo]

skizo.. Weber suggest W1 for use in hifi.
https://www.tedweber.com/ws1

Yeah, yeah, yeah ... the devil made them do that ... <G>

Apparently, that's been their recommendation for years, but they never made a lot of fuss over it. Did a web site redesign a bit back, and that showed up. In the meantime, the WZ68 was the copper cap of choice for many many rigs without incident. And, with the WS1, you lose the slow start that was a nice feature of the WZ68 due to the loss of the internal thermistor. There HAVE been some reported heat related failures, but that's more of a fluke, and the only damage is to the copper cap, as they fail open. I've heard of folk who simply pop the top and drill some holes top and bottom for better cooling.

Truth be told, the original recommended replacement for a 5AR4 was the WZ34, but the WZ68 can handle twice the load, is fully pin compatible, and cost the same. Pretty much a no brainer there.

But ... take that for it's historical value I guess, and do what ya gotta do.

PS ... I've already got a thermistor on the AC incoming, so it wouldn't bother me any, but I already got a WZ68. And, I only use that for backup, as the Mullard GZ37 has been doing the duty for years now, and, I've got a couple of those in reserve.

Oh. Not to bore anyone to tears with yet another ad for these little guys ...

Handy device to prevent system shock in case of a power blip. Those quick power flashes can kill tube equipment, as that all needs to discharge properly before getting hit with another inrush surge. Any blip trips the device and requires a manual reset. Best $20 you can spend for protection.

TRC 90033 Shockshield

 

[Lavane]

@vaathi Yet in their description, its stated that if you do not have a standby switch NOT to use the WZ1. to replace a single 5AR4 in an ST70 or in an ST120 the WZ34 or WZ68 would be better, no?

 

[sKiZo]

I think Ted Weber hates that audiophiles ever discovered the copper cap, and I'm sure he regrets ever getting involved in the argument of which is best for an application they weren't really designed for ... <G>

 

[Lavane]

I think Ted Weber hates that audiophiles ever discovered the copper cap, and I'm sure he regrets ever getting involved in the argument of which is best for an application they weren't really designed for ... <G>

And then grumbles all the way to the bank. As to the OP's question, I have a tubes4hifi ST70 and really like it. Very good instructions and great support as well. If you like it really loud then the ST120 or the mono blocks would probably be better. That being said, even with just 91db speakers my ST70 gets pretty darn loud. Although im happy with the ST70. I do sometimes wish I had gone with the ST120.

 

[Drummerboy2]

I have been giving some thought to trying a kit build of these amps. Dynaco has kits and tubes4hifi also has kits. I'd be interested in hearing from anyone out there who has gone down this path and after living with it for awhile what would they recommend?

I will be using Magnepan speakers but I can also use Dhalquist DQ-10's or Shihininian Obelisks. I like light classical as well as rock.

I would recommend going with the Latino VTA-120. It's a really nice sounding amp and has good power. I would get the GZ37 per sKiZo advice, as the GZ34 will not be up to the task for loud playback. I took his advice on this and have been trouble free with my VTA-120. I did get a Weber WS68 for backup. From my conversation with Bob Latino, if you want to play loud and get all the power this amp has to offer, he said to go with the Weber WS68.

I still need to do get the adapter to use a 6SN7 in the splitter spot. This is supposed to take the VTA-120 to another level per sKiZo.

 

[airtime]

I have the Latino ST-70 with Gold Lion output tubes -wow!!! I just love my 70!!!

It drives my 86db monitors quite loud if needed. But I would bump it up to the ST-120 or the monoblocks.

 

[eickmewg]

I agonized some over this decision. I decided that the VTA ST120 was the way to go. For only a small increase in cost, it seemed to have more flexibility for down the road. The only change I would have made to my order would have been to buy the kit without tubes. Also if it would have been an option that I was aware of at the time, I would have gotten a kit with the octal driver board to use 6SN7 drivers. I am confident that Bob could provide such a kit option for those wanting the octal tubes. After several years using the original noval board, I got an octal kit from tubes4hifi and I like that much better than the original board. My guess is that there would be no price increase for this option. I really think the 6SN7 tubes improve the sonics.

 

[Lavane]

I ordered mine without tubes and ordered them separately. I did order the capacitor upgrade and the volume control. The volume control replaces the seldom ever used mono/stereo switch. with the volume control all you would need is an input selector for a CD player, tuner, ect. You would however need a phono preamp if you are using a turntable.

 

[HiFiThor]

I agonized some over this decision. I decided that the VTA ST120 was the way to go. For only a small increase in cost, it seemed to have more flexibility for down the road. The only change I would have made to my order would have been to buy the kit without tubes. Also if it would have been an option that I was aware of at the time, I would have gotten a kit with the octal driver board to use 6SN7 drivers. I am confident that Bob could provide such a kit option for those wanting the octal tubes. After several years using the original noval board, I got an octal kit from tubes4hifi and I like that much better than the original board. My guess is that there would be no price increase for this option. I really think the 6SN7 tubes improve the sonics.

I have noticed that many of the 70's I have witnessed in the flesh have a cooked circuit board for the driver tubes. Mounting the tubes on the board does not allow the heat to escape. Maybe if the 6SN7 are used this won't happen as their is more clearance. Not sure about the sonics. Where do you find tubes at a reasonable price? What's wrong with the tubes they (VTA) supply? What are the "best" tubes (brand) to get? How do you know what is snake oil and what's not?

 

[CVElectronic]

I think Ted Weber hates that audiophiles ever discovered the copper cap, and I'm sure he regrets ever getting involved in the argument of which is best for an application they weren't really designed for ... <G>

Ted Weber actually died about 3 years ago, so I don't think he cares at present. I believe his heirs run the company now.

 

[Lavane]

Many of the newer boards are made of sterner stuff. As for the power tubes, tubes4hifi only offers two. EL34's and 6CA7's. The EH 6CA7's are supposed to be a pretty good tube, but you can find them around $20 cheaper for a Quad set elsewhere. Then there are KT66's, KT77's, KT88's and a few others you can use that they dont offer.

 

[CVElectronic]

I have done two pairs of Dynaco MkIIIs with the tubes4hifi boards, and I really like the results. The new driver circuit elevates the MkIII to an entirely different performance range in my opinion.

My only dissatisfaction is that the circuit boards themselves do somewhat limit one's parts choices, particularly in terms of coupling capacitors, but that's due to Dynaco's original circuit layout with one tube and the challenge of fitting a more complex circuit into that slot. Also, you do kind of have to know what you're doing with these kits because the schematics and parts lists sometimes contradict one another in minor ways.

 

[Lavane]

As for brands, everyone has their favorites. I really like the JJ KT77's. About the same cost as EH6CA7's. The 77's are a nice balanced sounding tube. I have a set of JJ KT88's that sound ok, but i found the midrange kind of layed back. Lots of low end though without being boomy.