SUT With a Manley Steelhead RC?


I own a Manley Steelhead RC and am using as my main cartridge a My Sonic Lab Signature Platinum.  MSL makes their own SUT that I have been thinking about purchasing, but I'm wondering if it's necessary with the Manley.  I find the Steelhead to be the best sounding phono preamp I've ever owned, but I'm always wondering about ways to make it even better.

I sent a message to Bob at Bob's Devices, but his reply to me was ambiguous.  He made it sound at first as if there would be little sonic benefit, and also seemed to say that his SUT would be superior to the one inside the Steelhead.  I tried to ask more questions but he went radio silent after that, and if I try to call their phone number I can't seem to talk to anyone.  This is not a complaint about their company, BTW.  I've heard nothing but good things about his products.

Any useful advice is appreciated!

128x128snackeyp

I still don't know what is a Veloce in terms of audio functionality.  If it uses 6H30, I assume it is a linestage which you used to replace the Lamm. Yes? I have a strong bias against the utility of spending huge bucks (like $22K and up for Lamm) on a linestage, but that's just me.

I found a blurb I once wrote about upgrading the Manley Steelhead v2.0.  I saved it on my computer, because so many people asked me about it, and I got tired of re-writing the idea for each inquiry. I don't know whether earlier versions of the Steelhead are built the same way or whether the Chinook is also comparable.  But here you go:

"I could not get a schematic; Manley does not provide a schematic even for professional repair shops. But if you read an interview with Evanna Manley, several years ago in 6 Moons, she describes the output stage.  I won't reiterate her summary (please google it; look for the Steelhead review in 6Moons) but suffice to say that the output of the phono stage, which either drives the volume control if you use it as a full preamplifier or the outboard linestage, if you use it as a phono stage only, uses a 47-ohm resistor in series with the signal followed by a 30uF output coupling capacitor, which in my opinion is mediocre in quality, at best.  This capacitor and what follows are holding back the performance of the Steelhead, IMO.  I removed the 47-ohm resistor entirely; it's not needed, and I replaced the  30uF coupling cap with a much higher quality 10uF capacitor. (Choose whatever you like but spend the $$$ for a very good one.)  You need 10uF, I guesstimate, because the volume control seems to have a 5K ohm input impedance (very low).  (10uF driving a 5K ohm load will give you a very low bass cut-off; 30uF is way overkill.) If used as a full function preamplifier, the output capacitor drives the attenuator as noted, and the attenuator drives the linestage. The linestage itself is nothing but a White cathode follower; it adds no gain to the signal from the phono section, but it provides a very low impedance output to drive any amplifier. The output from the linestage section (after its White cathode follower) uses yet another 47 ohm resistor in series with yet another 30uF capacitor of the same type and brand. That connects to the linestage output jacks. I removed that 47R resistor and replaced THAT capacitor with a 4uF film cap that I like very much.  Since my amplifier has a 50K input impedance, 4uF is more than adequate to get good bass. Those two coupling capacitors, from phono stage output to attenuator and from attenuator to linestage output have everything to do with the SQ of the Steelhead. There is a lot of room inside the chassis to use just about any film capacitor you might want, but I would recommend the 10uF Dynamicap E (for “Electronic”) for the output of the phono section that drives the attenuator, and for example a 4uF Dynamicap E for the output of the linestage. Dynamicaps can be purchased from Michael Percy. Other choices are up to you."

Big difference to ditch the two OEM 30uF capacitors and those 47-ohm resistors. Manley chose those odd values, and the odd idea to insert that resistor at all, apparently to enable the Steelhead to drive high capacitance cables, like VERY high capacitance cables, like higher than I could ever imagine anyone using in the home. It's no wonder to me that some owners prefer to use the unit as a phono only stage; that at least gets one of those two (mediocre is a diplomatic choice of adjective IMO) 30uF capacitors out of the way of the signal. It's actually a wonder that the thing sounds as good as it does.

Whart, If you heard an improvement after adding the Lamm, it could be because the Lamm Reference linestage adds about 9db of gain.  Could be your phono gain (60 or 65db in the original Steelhead?) was a bit marginal for those very low output cartridges you were using. Just guessing.

@lewm- Yes, the Veloce unit I own is a line stage and it replaced the Lamm at the time.

I do remember the tweak/mod you described from an earlier thread here but your saved summary is helpful. I don't know the internal differences or running changes in the Steelhead.

Never had a gain issue as far as I could discern-- to me at the time, the unit sounded a little spare, lean. I remember when Six Moons reviewed the Steelhead and the writer had a grounding issue. I wrote to them at the time (dunno if the comments are still attached to the review) about how to solve it. Did have a discussion with Eva at around the same time-- she believed "less was more" by not having the additional electronics. I think it is all system interdependent. As I recall, I was running the Lamm ML2 SETs which are still my main system amplifiers. It was around this time -2013?- that Alan Sircom came to visit; we had some lovely bone in rib-eye steaks that I grilled and a few hours of listening. Alan did a nice write up in HiFi+ at the time. 

..."the unit sounded a little spare, lean..."  In my experience, that sonic character is very often associated with marginal phono gain, and when higher gain is provided, the coloration is ameliorated. But if you are saying it sounded lean even after you inserted the Lamm, then all bets are off, except maybe you were hearing the Lamm, which after all is another device in the pathway that could potentially introduce its own sonic character.  On the other hand, I am in no way saying the Steelhead is flawless.  However, it sounds a whole lot better post-modification.  I am now thinking of upgrading the attenuator, but I hate to give up the luxury of the remote volume control.

Nope Lamm did not make it lean, just the opposite- put more meat on the bones, though the frequency extremes were rolled off compared to the Veloce (line stage comparison). As to lacking gain, perhaps that was an issue. It was a couple of iterations ago- sonic memory is imperfect, just remember the processes I went through. The mod you did seems to make sense. I did go back to that Six Moons review- it was apparently edited after the grounding issue was sorted and some newer material added. It's been a while.