[Macrel]

I own Apogee Duetta Sig. planar ribbon speakers and the Spectron Musician III SE Power Ampilfier. I also have an old Sound Valves VT100 preamp. I love the combo, but find the sound slightly edgy in the highs. I am considering a Modwright preamp, or another vacuum tub preamp to hopefully tame the beast a little - soften, warm-up, relax the sound a tad.

I would be interested in any preamp recommendations or experiences. I am also considering deHavilland preamps which to me sound musical and a little warm of neutral.

I also wonder whether I should invest in power conditioning ...? I live in a rural area, not many neighbours.

Thanks, Macrel

[opnly bafld]

SAS Audio has 3 very good preamps from $1k up to $3k.
The 10A (starting at $1500) and 11A have a 3 position tonal balance switch that works very well at this:
"tame the beast a little - soften, warm-up, relax the sound a tad".

http://www.sasaudiolabs.com/home.htm

Lin 

[Imperial]

You could also try to polish all metal surfaces in rca's, cable ends, speakercable spades and poweramps connectors.
Polish even your powercable plugs as well. Get that oxidation away.
Some times oxidation can be heard as harsh highs.
worth a little effort I believe this.
Depending on how high your ceiling is, you might be experiencing what is known as high frequency ceiling bounce...dampen the roof a bit midway between you and the speakers... auralex sonoflat could work. - The side walls or even the floor, if it's hardwood or something could be contributing as well. A circular rug maybe? Again placed midway between you and the speakers.
The second generation Duettas incorporated a 2db rolloff in the highs, that you might not have in your version...
What you could do is to get or build a diffuser to put behind them, to compensate..
Then there must be some type of filtermods one can do.
Change caps maybe? Gosh, lot's of stuff I'm sure that can be done!


---

Imperial

[richidoo]

The Modwright 36.5 is a great performer, but is not warming, soft or relaxing. There is one used on AC trading post right now if you wanna try one at a discount.

Cary Audio might be a good fit. They design around 6SN7 like deHavilland. 6sn7 is warm and a little dark, richening up the midrange tone. Cary is not rolled off, nor "relaxing" in my view, but everyone's relaxing is different. Modern tube preamps are not soft and relaxing like they might have been 40 years ago. Most are pretty clear and exciting, some more tasteful than others. With Cary, there are several designs. Their premier SLP05 if you are daddy bigbucks, or their budget brand AES AE-3.  I have heard both of these, and also owned a Cary integrated with same flavor built in preamp, it is all very nice sounding - classic 6SN7 Cary sound.  Warm, clear and rich. That little AE-3 does a nice job smoothing and warming. There are 2 others in the line. Look for a local dealer to borrow one.

The Manley Shrimp is a great little preamp, a little soft in the highs and a little compressed, but it is very listenable. A thick rich sound, hard to describe. 50 ohm output impedance might be the lowest of any all tube preamp! That doesn't matter for your Spectrons which are an easy load.

The Eastern Electric Minimax is worth a look, it allows easy swapping of 12AU7 tubes which come in every possible sonic flavor. From the stock Chinese tubes that I love that are low distortion and very extended top and bottom, to some syrupy Mullards or fat sexy Amperex, nice medium compromise RCA black plates. No doubt you can find a tube that will work for you. There are a lot of minimax owners out there which does three good things, keeps used ones on the market, keeps resale value good, and gives you the access to the combined experience of all those peoples' tube swapping. I got a LOT of help in trying different tubes from Bill O'Connell and carusoracer. I own a Minimax with the Morningstar mods, I have given up trying to find something as good sounding with the same kind of value.

I was fortunate to participate in a tour of the SAS 11A and really loved it, but I wouldn't say it is warm enough to be used as a band aid as you intend. It is designed to give minimal coloration and maximum speed and tonal refinement. It is extremely clear and uncolored. It is not noticably warm, but warmth can be felt, if not heard. The clarity and sense of space is addictive. It's 6922 tubes are sweet and slightly warming whereas 6SN7 as used in Cary and deHavilland in general can be more warming and are usually a little darker than nine pin tubes like 6922 and 12AU7. I have only heard the deHavillands at RMAF demos, but I view it as a step above the low end Carys in refinement, might be a nice choice for you.

I would love to hear a followup from you after you work it out. I am interested in the Spectron also, and I will stick with tube preamp.
Thanks
Rich

[jon_010101]

Not to be an ass, but why gamble?

Invest in a high-end tube preamp with high-end tone controls, to provide some flexibility! 

Picking sound via different kinds of tubes is a total crapshoot, and a recipe for dissatisfaction. 

Now, it may be that your existing preamp has some kind of annoying distortion, too... so if you can try something else with no tone controls and see if it improves... that would be a good step forward.  Or, if the 2dB Duetta difference is a consideration... maybe get the crossover tweaked.

[wilsynet]

Could you also say what you have for sources?

As for recommendations: Red Wine Audio Isabella.  Warm of neutral.  No need for power conditioning. 

Great review on 6moons:

http://www.6moons.com/audioreviews/redwine10/isabella.html

It's known for being relaxed *and* resolving.  The optional DAC has the same character, which solved all of the harshness/edginess/brightness issues that I used to have but have no longer.

[TheChairGuy]

I could never tame the edginess until I ditched my SS or 'digi' amps for tubes.

Solid state preamp and tube mono amps have been my ticket to the good times 

It might sound counter-intuitive...until you hear the tandem in action 

John

[KS]

Dodd battery powered preamp

6moons:
What is it then? Well, for starters, suave, dynamic and clear. Three words that in my experience one will rarely find strung together to describe even above average electronic components. The Dodd is also genuinely detailed, meaning not just for the sake of detail but to the ends of delivering newfound musical lines and expanded instrumental subtext. With brilliant transient attack, you can expect to be (usually pleasantly) startled even as you anticipate the beginning of familiar tracks. And once into the groove, you'll be rewarded with the level of transparency one would expect to come from the absence of a power cord.
http://www.6moons.com/audioreviews/dodd/dodd.html

[ArthurDent]

Nothing to speak of in the comparitive experience dept, but I find my AVA Transendence-8 very warm and engaging. Haven't seen any negatives from anyone here on A/C about their satisfaction with the sound. No tone control, but haven't really missed it. You can find numerous discussions on Frank's circle, and fwiw it recv'd the Absolute Sound Award for best in it's category.

Good luck in the search.

[AliG]

Sounds like you need an Audio Research Reference 3  - high resolution, airy top, a little bit of tube sound that adds 3-dimensionality but not too much. Very good match when paired with SS/class-D amps.

Last but not east, ARC gears has established resale values.

[2gumby2]

I recommend taking a look at what Ray Samuels has to offer  www.raysamuelsaudio.com    I had one of his Raptors and I can't imagine a better designed better made unit. His workmanship is amazing and his customer service is outstanding.

[Occam]

Marcel,

Why do you assume a different preamp is going to fix your problem? You don't describe either your cables or power delivery. I've yet to hear a class D amp with either a linear or switching mains power supply that didn't, especially in terms of midrange and treble glare, benefit tremendously from appropriate power conditioning. Or have you considered the tube complement in your present preamp? I don't know the topology of you preamp, but in my Cat-1 preamp, substituting a Tung-Sol reissue 12au7 for a RFT, would certainly removed glare (in my system). Substituting Cardas Quadlink 5 interconnects for my Au24s would do similar. As to where your problem lies, dunno, but simply swapping preamps may not be the ideal way to go about. Then again, it might be an the optimal change.

FWIW,
Paul

[JackD201]

  Or, if the 2dB Duetta difference is a consideration... maybe get the crossover tweaked.

This would be the most cost effective fix IMO. One pair of resistors can do the trick just as it does with Magnepan who supplies these with their speakers.

There are lots of second hand CJ preamps around. Their house sound favors those folks looking for mellow, full sound. The lower the model the mellower they are.

Good Luck!

[satfrat]

There's a lot of things that can cause scratchy highs and there's a lot of things you can do to combat it. I like Imperial's idea of polishing all your connections, starting with your AC plugs and all the way to your speaker's terminals. This is what I do, get some 000grade steel wool and Pro Gold GxL, polish and clean everything metal. You never mentioned what you're using for IC's & SC but that'll make differences also. And power conditioning, I'm a firm believer that you can't get your power too clean as it's being attacked all thru out your system as it is. Crappy power from the wall will only compound the issue, especially the highs. Crappy power could actually be your problem. I'm in total agreement with Occam and that's where I'd start.

Cheers,
Robin

[Macrel]

Thank you one and all for your suggestions. That's a lot to consider! Someone asked about my source: All digital (FLAC). Computer to Sonos through a Benchmark DAC1 to preamp. Another question about my power source: Power amp is direct to wall socket - no conditioning. All other components are plugged into a Monster Power box. All wall sockets used are on the same circuit. Speaker cables are Nordost Blue Heaven, Interconnects are RCA, Virtual Dynamics - David series. (I know these cables are all considered a little dry and clinical - so this may be an area to improve).

One other observation, it does seem that the sound varies from day to day (power??) . Some days I find the highs a little edgy, while other days not. (Is it me?)

I tried removing my preamp and went from DAC1 directly to amp and that was extremely clinical and not pleasant.

Thanks again. This is a great forum.

[woodsyi]

Definitely clean you interconnect.  Before you plunge into a pre-amp carousal, I would borrow a different amp and see if it's the Spectron amps that is causing this with your ribbons.  Some people hear switching amp "artifacts" more than others.  The clean, powerful and incisive presentations good switching amps can provide can sometimes cross the bound into shrillness especially when playing a digital source.  I sometimes wonder if the decimating low pass filter in PCM still leaks signals in high frequencies that amps, especially the switching type with all the pulse modulations, somehow pick up and amplify the leakage to the extent that some can hear the "folded down" harmonics in the audible region.  I am just trying to rationalize empirical findings with little knowledge that I have.  Don't laugh at my amateur rationalization if it's way off base.  I would try a non switching amp and see if you still get the same experience. 

[GBB]

I've yet to hear a class D amp with either a linear or switching mains power supply that didn't . . . benefit tremendously from appropriate power conditioning.

I think that Paul is right on the money with his recommendation for power conditioning - especially of the class D amps.  Especially in light of the following comments.

One other observation, it does seem that the sound varies from day to day (power??) . Some days I find the highs a little edgy, while other days not. (Is it me?)

My experience is that variation in sound quality over the course of the day is always due to the quality of the AC.  During the day there tends to be a lot more "garbage" on the line and your system won't sound as good.  Late at night when businesses are closed and more people are asleep, the quality of the power seems to be better, and the sound can also be a lot better. 
A good quality power conditioner such as the Audience Adept or Occam's DIY Felix can make an impressive improvement.  I'd see if I could borrow one of these and check it out in your system.

---Gary

[wilsynet]

Certainly clean AC can be a significant factor (I'm using a battery powered DAC and integrated amplifier myself).  I have a Balanced Power Technologies CPC (with isolation transformer upgrade) that I don't use anymore since I moved to battery power -- I can loan that to you if you're interested.  If you're willing to take care of shipping, I'll gladly loan it out to you.  PM me if you like.

I wouldn't be the first person to say that the Benchmark DAC is cold, sterile, and hyper analytical.

Having owned both Benchmark and the Electrocompaniet ECD-1, I found I couldn't live with either long term.  The highs were just too high, too edgy, too digital, and made my ears bleed during extended listening sessions.  Not everyone feels this way, but I do ...

Of course, I'm not familiar with all of your gear, but it wouldn't surprise me if the Benchmark was a big part of this.

I found that if I got a very warm tube preamp or tube integrated, a very warm one, euphonic even, then I could live with the Benchmark.  But then I lost dynamics and neutrality.  In the end, the solution for me, the long term solution was a NOS DAC.  There are a number of good ones, depending on what you need.  It sounds like you need a DAC with at least SPDIF input.

The MHDT Labs Paridisea+ is well regarded here, as is the AudioSector NOS DAC from Peter Daniel (highly recommended as punching way above it's weight by AC members Bucky and Pardales, and one of my personal favourites too).  More upscale is the Altmann Attraction and the Red Wine Audio Isabellina.

[Occam]

Marcel,

Given your experience with taking your preamp out of your system, it seems that your pre is not significantly contributing to whatever harshness/stridency. I'd suggest you do a similar experiment with taking the DAC-1 out of the system and listening via the analog outputs of your Sonos, feeding your tube preamp. I'm not suggesting the Sonos would satisfy your needs regarding resolution, etc... but it will allow you to judge whether the DAC-1 is a significant factor regarding harshness. I do agree with wilsynet's assessment of the DAC-1. Stereotypes are good, applied to stereo equipment or people, because they save us the effort of having to think or experiment for ourselves.   But in this case, its rather easy to verify for oneself.

This is not to say that mains power delivery/conditioning isn't a significant factor in your quest. (I manufacture power conditioners/cords) Its just that inevitably, tuning a system involves more that simply changing one thing.  Its simply easier to to try to make some conclusions about your components with the things you have at hand, first, and armed with that information, then proceed with efforts that require you to buy/evaluate additional thingamabobs.

Regards,
Paul

[Occam]

Marcel,

Assuming you're in North America, I would suggest that your swap out whatever outlet(s) feed your system for either a Hubbel HBL5262 (15A) or HBL5362 (20A). These outlets are subjectively a bit warm and sweet, yet extended and resolving. They're available from stayonline.com for $12 & $14 respectively. Their website is presently 'hinkey' so I'm not providing direct URLs.
I'd also suggest you ditch the Monster powerbar for something like-
http://www.b-p-t.com/ppc-pure-power-center.html
But you've yet to resolve what (or if anything) you'll be doing with your power delivery. If you ultimately choose a conditioner the has multiple outlets to power different components, a powerbar might not be needed.

Regards,
Paul

PS- Both JenaLabs and Alan Kafton offer cryoed versions of those Hubbel outlets, which are said to offer even greater improvements, but I'm not personally familiar with them.