Into the dark abyss I go again....

[manlystanley]

Give some consideration to upgrading the capacitors in the direct signal path. You might consult the "Great Capacitor Shootout", (here), which link was originally supplied by RGA as I recall. Obviously you can spend absurd amounts or money on capacitors

Hello Feanor,
You are the man!!!! errr.... maybe macho Elf Lord is a better title?? Anyways, I'm planning on using this Capacitor Shootout to optimize the sound. Very, very good information. I try to give back to this group, but I always seem to get so much more then I get!!

Best Regards,
Stan

[Feanor]

Hello Feanor,
You are the man!!!! errr.... maybe macho Elf Lord is a better title?? Anyways, I'm planning on using this Capacitor Shootout to optimize the sound. Very, very good information. I try to give back to this group, but I always seem to get so much more then I get!!

Best Regards,
Stan

Yer welcome.

The Mundorf MCap Supremes look like a great deal. Note that they are listed under 'AAA' for AC line filters because they are the only AAAs what are 'X' rated, however they can because used elsewhere too.

[Geoffcin]

Hello Feanor,
The choke is used to connect the power supply to ground. Without it, the power supply is directly grounded to the chassis. The purpose of it is to attenuate output feedback that come from the amplifier and goes though the ground plane back to the Power supply, and vis-a-versa.

One of my amps, the Musical Fidelity A3cr, uses choke regulation and it's a very quite amp. An unusual desing for a SS amp, but it works very well.

[manlystanley]

Wanted to give you all a little status on how my preamp is going:

-- I've been stuck with it for about 3 weeks. I'm studying for a certification test (CISSP) that I take this Saturday and I've been giving my full attention just to the test.

-- I've got all amp parts and with some help of some friends I've got a good design of the Rk and power supply so that I can get a 250 volt B+.

-- The tubes that I'm using will be: 5687 and the 6CG7's. Both of these tubes have heavy heater draws, so I've got a beefed up low voltage supply.

-- I got the chassis all wired up with the remote controlled volume control. I hooked up the new preamp with just the remote controlled volume control and it works great (e.g. sound was great. Very different then with my current Adcom. There is a HUGE amount of bass. It worries me that may be the final result will be bass heavy.


-- I have the Aikido amp itself all soldered (except for a few jumpers that I'm not sure what to do with).

-- When I have time, I need to: Solder the power supply; put it in and give the system a look see.

I'm taking my family surf fishing next week (after my Saturday CISSP test) in North Carolina. Then I plan on finishing up the project. I'll make sure to tell you all how it sounds!!

Best Regards,
Stan

[manlystanley]

Wanted to give you all a little status on how my preamp is going:

-- I've been stuck with it for about 3 weeks. I'm studying for a certification test (CISSP) that I take this Saturday and I've been giving my full attention just to the test.

-- I've got all amp parts and with some help of some friends I've got a good design of the Rk and power supply so that I can get a 250 volt B+.

-- The tubes that I'm using will be: 5687 and the 6CG7's. Both of these tubes have heavy heater draws, so I've got a beefed up low voltage supply.

-- I got the chassis all wired up with the remote controlled volume control. I hooked up the new preamp with just the remote controlled volume control and it works great (e.g. sound was great. Very different then with my current Adcom. There is a HUGE amount of bass. It worries me that may be the final result will be bass heavy.


-- I have the Aikido amp itself all soldered (except for a few jumpers that I'm not sure what to do with).

-- When I have time, I need to: Solder the power supply; put it in and give the system a look see.

I'm taking my family surf fishing next week (after my Saturday CISSP test) in North Carolina. Then I plan on finishing up the project. I'll make sure to tell you all how it sounds!!

Best Regards,
Stan

[manlystanley]

Well, a passive preamp consists of an input selector and an attenuator and about that's it.

It seems to me that basicaly you could build one with this remote control selector + attenuator like this one, (here), from DIY Gene, $40, plus the requisite power transformer for the remote function, (here), $20, and a case like this one, (here), $60. It would cost you around $120 plus shipping.



(Wow! I'm thinking I could go for that myself!)

This is the remote control that I got. It needs a separate 12v transformer, but I'm very pleased with it.

[Mr Peabody]

Eeew doggies, listen at you talk, sounding all fancy like a technician or something Good deal Stan, looks like you are having fun.

A bluming bass can sometimes be a trait of some tube gear, hence the stereotype. It sounds like you put a lot of research into the project hopefully when all is settled it won't be bad.

[Dawnrazor]

Any hint of digital edge was removed (even with my SS amp but I'm also using a tube DAC which may be another option for you instead of a preamp. The Tube DAC probably made the most impact in sound for me.).

Hey BR,

My hunch is that your mags are probably to blame for the digital edge. Placing some 5522 chokes from mouser:
http://www.mouser.com/ProductDetail/...%252bOcg%3d%3d
in series with the tweeter will do wonders to tame the digital edge.

I was shocked when I put them on mine, and the bass panels too. I never thought I had any digital edge though when I put these on it was amazing how warm things became.

The idea is that the mags are radio antennas and RF can get into the amp and modulate the signal which typically sounds like digititus. This can be rf from existing gear like cdps or from neighbors wifi, etc.

Anyhow well worth the 10-20$ if you have maggies.