Let's discuss the different head amps folks are using...or SUTs

are you using a vlomc cartridge with the stm-72?

that unit has lots of gain, having been designed to go with Ortofon's MC20 with a 0.07mV output. The more expensive MCA-76 was the head amp for that cartridge and its gain is spec'ed at 34.5dB, much higher than the typical 20dZB or so.

Correct....when I had the MC20. ;)

Also had the MCA-76 which I sold with the cartridge some many years back.

Now the STM-72 sits and waits for the time when I buy another MC20 or other VLOMC to match it.
 
One day I will have a cartridge suitable for comparing my Cinemag 1131 SUT to my Fosgate Signature's MC setting, I hope.

I have a Marcof PPA (pre-preamp, i.e. head amp) from the 80's that works and sounded decent the one time I've listened through it. The Marcof is battery powered.
 
I know that this probably makes me an anachronism but I usually run good old Denon DL-103 MCs into the Quicksilver SUT.

It is a sound that I really like.
 
I have one SUT, the MC SUT for the Crown SL-2 preamp. This preamp had only a MM phono input and Crown offered an SUT for it to allow the use of LOMC cartridges. I didn't even know this unit existed but picked it up off the bay a while back. I can use it with MM inputs, the MM Crown phono amp for the DL-2 or SL-1 preamps (two different units) and such. I don't have any documentation for the unit but it isn't too hard to understand.

Be nice if I could learn the proper way to measure it to determine it operating parameters. I just need to continue my electronics education I guess.
 

Attachments

  • SL2-MCa.jpg
    SL2-MCa.jpg
    92.5 KB · Views: 36
Last edited:
Using a Yamaha HA-1 MC cartridge amp (pic from web) into a DIY phono stage by AKer MJarve:

Yamaha HA-1 Specifications
Voltage Gain Low: 34dB
Voltage Gain High:14dB
Maximum Input Low: 30mV
Maximum Input High: 300mV
Input Conversion Noise Low: -157dB
Input Conversion Noise High: -144dB
Frequency Response: 10Hz - 500kHz +0db -1dB
High Frequenct Distortion: Less than 0.005% (5mV Input 20Hz-20kHz)
Output Impedance: 100Ω
 

Attachments

  • 68853.jpg
    68853.jpg
    62.8 KB · Views: 37
And now for something completely different . . . (not really)

My TD-125 Mk II is currently up on blocks waiting on a $1.50 replacement bulb from Spain or Portugal for the Wein Bridge circuit. While I'm waiting, I picked up a used Graham Slee Elevator EXP head amp with a flat 20 dB of gain on the bay. The Elevator's PSU is for the EU @ 230V, 50 Hz, so I'm putting together one of John Broskie's Glass Audio power supplies instead to make it go.

I really want to hear how the Elevator's performance into a good tube phono stage (a stock Bottlehead Eros) compares to my DIY SUT with Cinemag 1254 xformers, solid silver wire and WBT RCAs.

The carts I have in the drawer to try are a DL-103, an Expert Stylus newly retipped DL-103R, and a Stanton 980 LZS (a very-low output MM cart sporting a stereohedron stylus available NIB from William Thakker, although the price recently went up like crazy and it'll now cost you an arm and a leg).
 
I like the adjustability of that H-Z1.

Last night I put a voltage into the Crown SUT designed for the SL-2 preamp since it had a phono input and Crown made MC cartridge inputs available on the SL-1, SL-2 and DL-2 preamps. It had about 17dB of voltage gain. I know I need to test it more but I at least know now where it fits in my MC handling equipment.

Does anyone have experience with the Luxman silver wound transformers either plugged into the LRS 5C50 preamp or the L-11 integrated and a couple other units or as a standalone using the AD8000 base? These were the 8020, 8025 and 8030 units.
 
I have a Musical Fidelity AC-1, had two but sold one and Tom Clone bought a third one but no one has any of the paperwork for it. Since I bought mine with a consignment TT back in 86, it is from the same era at the SOTA. The AC-1 is also fully shielded, but has set gain and internally fully adjustable cartridge loading (by installing resistors).

I think we have bumped into each other before. :D I picked one up a year or so ago. No specs, but I have been meaning to find out what the loading is set at by default, so I am not guessing at what load I am using. (I may finally get a chance to measure it the correct way.)

Thing is, it has a bit of a "rushing" noise so I believe it's either not running optimally (old caps maybe?), or may just be noisier than I'd like it. In a couple of months I am going the Cinemag route and just using a SUT. I am waiting to see what turns up in terms of preamps first. If I find one I like with a MC input, I won't have to bother.
 
Does anyone have experience with the Luxman silver wound transformers either plugged into the LRS 5C50 preamp or the L-11 integrated and a couple other units or as a standalone using the AD8000 base? These were the 8020, 8025 and 8030 units.

I've got a Lux 8025 plugged into a LRS 5C50. Sounds great, but I'm not certain if it's drastically different sonically than the CX-1 head amp I was using previously. The transformers are heavier than I thought, and hard to find.

Looking for an AD8000 so I can migrate it amongst other equipment.
 
Luxman did a lot of work making their equipment sound good. If the same folks were doing the listening I would expect the CX-1 and 8000-series SUTs to sound similar. Maybe the silver windings of the transformers would add a flavor to the sound, too.
 
My preamp hunt continues--it seems I may end up getting a tubed linestage, and then will need an outboard phono preamp. Would prefer tubes there also, but it is not set in stone. And even there, I have no guarantee that they'll handle MC without a step-up.

Looking over the Cinemag offerings, the CM-1254 transformer is the second best; the CM-1131 is similar but hand-wound by the company owner. Would I even notice the difference between the CM-1254 and the less expensive CMQEE-3440AH? Parks Audio sells both of these in assembled enclosures.

Another transformer is the Lundahl, and the LL1931 is the better of the two. A little company named K&K Audio lists kit and assembled versions.
 
I don't really know anything technaly about this kind of stuff I just plug things in to see if they work....:D

Truthfully It had a SOTA name on it at the auction site and I had to have one. The end result was it works good within my system. I have had other stand alone stages and nothing sounded as good. The Coph Nia was close but good luck finding one of those, I had #8 & #9 and sold 8 and still have 9 it was a Michael Fremer test unit.

It's your thread and nobody uses head amp and I don't know why. But if one is into vinyl, MC carts and wants great SQ they need to start looking at these "Head Amps"

To be truthful their is not much inside those Sota tubes, basically a small battery powered amp, and since its gain output is low, power requirments are low. The head amp or a phono amp is pretty much the same thing it uses a power supply to increase the signal of the input to increase the output.

Where as a SUT is nothing more than a step up transformer. The number of windings on the Primary side in ratio to the secondary windings is what determines the increase in output voltage, where as current drops converserly.


325px-Transformer3d_col3_svg.png


In most cases the SUT should be less likely to incur noise if well shielded. As in the case of the Sota's the use of batteries reduces the chance of noise that can be introduced by a less then quality power supply. Many DIY or modified phono amps are ones where people remove the power supply and use batteries to help decrease the introduction of noise by the power supply. In most cases the SUT would not have the increase in gain as a powered phono stage. And those head amps seem to be a bit lower in gain than many of the newer phono amps out their now. Possibly the later batch of LOMC's are in need of more gain than the earlier MC's so the need for more gain is a by product.
 
The LOMCs I've owned actually have increased in output in recent revisions, but I haven't followed others to see what the trend was.

For a Cinemag setup, I am not sure whether I want to attempt doing my own circuit board and building it into a shielded case, or buy a pre-built version.
 
Circuit board in an SUT with cinemags, probably not necessary. Take a look at a few of the home built units and you'll see it is just mounting the trannys and connecting wiring in and out to the jacks chosen, usually RCA. Pretty easy overall. Even if there is a gain choice or something that is just adding a switch and wiring. Point to point wiring.

@Ken Boyd do you have a good site that converts winding ratio to gain? Another page to look at would be one that could take the cartridge output and gain or winding ratio and produce the Head Amp/SUT output level so folks can match gains appropriately.
 
Winding ratio for the most part I believe is close to the ratio of the windings. So using just some numbers say you have one watt, going into a transformer that has 100 windings on the primary side and 200 windings on the secondary side you double the voltage and half the gain, with a small percentage of loss, at least that is what I recall from my basic memory .
 
Yes. Any transformer would increase voltage but decrease current in one direction, or decrease voltage and increase current in the other. And I'm sure there is a bit of a loss in there but I don't recall how much.

That is how we get AC delivered to our homes. So the high tension wires do not have to be very thick to carry a lot of amperage (current), they use a very high voltage instead. In the neighborhood, they then use a transformer to change the high voltage to a lower one, providing far more current.

And man, are they noisy when they blow. :D

Circuit board in an SUT with cinemags, probably not necessary. Take a look at a few of the home built units and you'll see it is just mounting the trannys and connecting wiring in and out to the jacks chosen, usually RCA. Pretty easy overall. Even if there is a gain choice or something that is just adding a switch and wiring. Point to point wiring.

I'd considered it but if given a choice, I'd prefer a nice quality circuit board. I'd still get a nice aluminum case though.

Ideally I'd thought of wiring up transformers right inside of a preamp, but many have the RCA jacks soldered directly to a circuit board these days. And, I don't know if the inside of the preamp case is too "noisy" (EMI/RFI) for the transformers.
 
Well, I cured my "problem" and now have a Musical Surroundings Phonomena II+. So far, so good! As I often work from my home office, I ended up spending most of Tuesday playing records.

With the XX2 Mk. II, I settled on 59Ω loading, but may try 50Ω again--I can't decide which I like better. 40Ω was too dead. Anything higher than the 59Ω seems too bright to me. Gain is at 56dB.

I really like the loading flexibility on this unit. I realize it's not truly a SUT or head amp, but there's a part of me that is liking not having an extra component and set of interconnects in the chain (SUT to phono stage to preamp, in other words).
 
Although this is the same number of extra components in the chain as using an SUT/HA into a phono stage in the preamp, without that phono stage there would need to be more gear. We like more gear in general but all in the signal chain isn't good.

We have had an MS phono pre here for a shoot out. It sounded very nice. You made a good choice not only for sound quality for adjustability to use with other cartridges.
 
Back
Top Bottom