Preamp

[Inscrutable]

OK ... the hardwoods are done (phew!) ... the Citation is in place ... going to start the long-delayed sub ... soon it's going to be time for another upgrade. This is for the 2-channel setup. I'm using a Yamaha non-digital receiver as a preamp, and was thinking of replacing it. I was considering trying a DIY, and wondered if any of you have knowledge/experience with either Doc Bottlehead's Foreplay (doesn't THAT sound good to the uninformed or Audio Electronic Supply AE-3? For 99 bucks, the Foreplay may be fun even if it's not very good or I screw it up - hard to imagine, I know

http://www.bottlehead.com/et/et.html

http://www.audioelectronicsupply.com/

Tim
"Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it." --- Goethe

[Lexman]

Tim, I been a bachelor so long now, I forgot what forplay is, or far as that goes any kind of play, lol.

Now, I am not familiar with these, but I am betting Jon is, maybe even Thomas.

and my your an ambitous lad!

Lex





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[JonMarsh]

Hi Inscrutable,

What are your needs or desires for a preamp? Do you really need 20 dB of gain? What sources will you be using it with?
The AE-3 preamp is pretty cute, sounds like it's basically well made, and at $399 for the kit, $599 assembled, the price is fairly reasonable. I've built some gear with 6SN7's back in the late 60's, and it's a nice tube. But.....

In my thirty plus years of experience with audio electronics, I've come to the conclusion that the volume control is one of the most critical elements of a preamp- and often one that is somewhat neglected. Let's not even talk about carbon pots (they're out there, still), but even conductive plastic and cermet have problems with operating lifetime, particularly depending on the contact wiper materials used. There are issues about subtle contact rectification from dissimilar materials, and issues regarding lifetime. The biggest problems I find with conventional volume controls is degradation of the sound at low volume settings, and with age/use.
As far as gain stages go, my conlusion is that the few active stages in the signal path, the happier I am. This is especially true with high resoution sources such as SACD, or high quality analog. That's why my most recent preamp is an "un-preamp", (passive), with no gain stages, and 55 step Shallco rotary attenuators for volume and balance. For $449, (kit), the Marchand PR-41 is a steal, sonically. It's not very pretty- I replaced the knobs with nicer ones, and I'm still thinking of making a new front panel, anodized aluminum. But, it doesn't have ANY sound of it's own that I can discern, which is the ultimate test. I couldn't say that about my last two store both premaps, both of which had MSRP's over $2K. Even my last DIY suffered in comparison to the Marchand, but I think that's because of the "cheap" $200 conductive plastic volume controls- the all discrete gain stage has passed a straight wire A/B test (dang, it should- 250 v/usec slew rate, input noise of 2.5 nV/root Hz, output swing that will drive 75 ohm loads easily).
So, if I needed gain, I'd pair up my discrete stage with the Marchand. But, with CD, SACD, and DVD as sources, I don't need any gain. Or power cord. Or on/off switch.

Just something to think about and ponder.
As Lexman has said frequently for other posters, if at all possible, audition before buying. That's really the only drawback to mailorder kits- pretty impossible to do that. But with a quality pure passive unit (there are others besides Marchand, but I'd call it a value leader), there's essentially no risk.

Regards, and have a good weekend.

Jon




Earth First!
_______________________________
We'll screw up the other planets later....

[ThomasW]

Well it's confession time . "Valves" don't do it for me, (surprised?) So, I'm really not in a position to comment, in that I don't follow the "development" of tube gear, (I'm not sure that isn't an oxymoron, sorry!).

I can appreciate the esthetic "sculptural" aspect of the designs, but that's about as far as my appreciation goes. I have friends that are S.E.T. fans, they get teary eyed describing what they hear. I just hear euphonics

That being said, the kits are reasonably priced and probably are a good value. As an investment, their potential is limited because this is such a niche' market.

These will certainly sound VERY VERY different from your receiver. I'd suggest that if possible you might "audition" a tube pre-amp from a dealer/friend/whomever. This will at the very least, give you some idea as to the sonic properities and how it might "fit" your needs/wants.

If you need a phono section, then a real pre-amp is a must. If all your sources have a volt or two output then I'd seriously consider Jon's suggestion.

Maybe MichaelW could comment on this.




theAudioWorx
Klone-Audio

[Inscrutable]

Jon,
Thanks for the ifo (I think!). I had meant to mention the PR-41, but you'd had a pretty long discussion about it in another thread, so I didn't bother. Aesthetics don't bother me - it'll be behind the door of a rack, anyway.

Thomas,
Yes I do have a phono, but could get/build a phono stage as well. As far as trials, I think a dealer here would let me borrow a C-J. Seems ProAc is demo'd a lot with tubes, usually Cary or AR, and for a hundred for the foreplay and some time it'd be worth it as a lark. Resale of a little known DIY brand would be pretty difficult, so I might not lean to the AES or Marchand until/unless I'd tried the el cheapo or borrowed a "mfr" unit.

Lex,
lol... and ambitious is ONE adjective to use - my wife would choose a few others




Tim
"Whatever you can do, or dream you can, begin it. Boldness has genius, power, and magic in it." --- Goethe