Muff's Modules & More

equalpyramid

I've been looking at some tube amp projects to power speakers. Now I'm not after anything "audiophile", but some of the cheaper kits at Tube Depot looked interesting.

Tube Depot Kits

So Eric, or anyone else that knows about tubes, are those money well spent? Any suggestions?

metasonix · Posted: Thu Jul 05, 2012 1:01 am Post subject:

The "cheaper" kits are literally built on slabs of wood. Safety hazards. If you build one, put it in a proper enclosure.

Any of them would be fine. Just realize, they are "hi fi" amplifiers, and not intended for music amplification. So they will have low voltage gain. You cannot use them as guitar amps, without adding an instrument preamp.

equalpyramid · Posted: Thu Jul 05, 2012 4:50 pm Post subject:

I see. My intention was to simply use them between line out and speakers for studio use only. If I can find schematics for the IMP amp (2 X 6021 subminis), then I'll build that one.

tablebeast · Posted: Tue Jul 10, 2012 10:41 am Post subject:

http://xfmr.blogspot.com/2012/06/brute-force-of-jekyll-hyde.html

tablebeast · Posted: Tue Jul 10, 2012 10:44 am Post subject:

I make tube amps that go great with the Metasonix stuff out of old Akai / Roberts tube reel to reel monoblock amps and have some DIY schematics available.
My Pre+Amp has a line input as well as a hi-z input so it can handle passive or active instruments as well as line level devices. It also has a dummy load on the speaker output with a padded headphone/line out jack so you don't even have to use a speaker and can listen or record directly. The two modes consist of a cleaner mode with negative feedback employed and a more driven mode with the feedback removed and gain boosted. When I build them into the Akai donor modules I always include the Brute Force preamp circuit in the same box since there is plenty of room and resources for it. This preamp can be used separately or in conjunction with the amp. Think of it as a modular tube amp: perfect for your modular tube synth!

equalpyramid · Posted: Wed Jul 11, 2012 12:43 am Post subject:

Wow, tablebeast, that's quite the DIY gear collection. Care to share some tips with us?

tablebeast · Posted: Thu Jul 12, 2012 11:24 am Post subject:

Moog$FooL$ · Posted: Thu Jul 12, 2012 11:48 am Post subject:

equalpyramid · Posted: Thu Jul 12, 2012 12:51 pm Post subject:

Moog$FooL$ · Posted: Thu Jul 12, 2012 2:29 pm Post subject:

Chrome Dinette · Posted: Sat Aug 11, 2012 7:15 am Post subject:

Eric Barbour wrote a project article in VTV, #10 I think, for an amp that was said to be suitable for hi-fi or musical instrument use. It was pretty complicated, though, and used tubes that may be hard to find now.

equalpyramid · Posted: Tue Aug 21, 2012 7:24 pm Post subject:

Okay, so following the great advice on this board/thread, I found an old PA amp that fits the bill.

It's a Soundmaster, made in Canada, and uses three 6sc7 instead of 12ax7 and 807 for power. I will change the elec caps before trying anything, but I'm stoked. I will keep it as a PA config for now, since it's for studio use only.

Moog$FooL$ · Posted: Tue Aug 21, 2012 8:03 pm Post subject:

wow! good find eqp. thumbs up

i'd love to see some pics.
please keep us updated.

metasonix · Posted: Wed Aug 22, 2012 2:40 am Post subject:

equalpyramid · Posted: Wed Aug 22, 2012 8:01 pm Post subject:

Moog$FooL$ · Posted: Wed Aug 22, 2012 9:20 pm Post subject:

eqp........ as far as "caps" how old is this thing?

eric's advice was solid...... change all the electro's. BUT!! what does it sound like & how's it acting? maybe you don't need to change them yet. seriously, i just don't get it

i've changed out numerous filter & bypass caps (electros of course) in many guitar amps & i like to buy from some nice folks at http://justradios.com/.

they're Canadian too. love

as for spragues..... i wouldn't waste the cash. i just don't buy into that "tube amp guru" bullshit.

ummm...... i don't know what else to say. hmmm.....

maybe tablebeast or eric have some more help.

anyways, i'm in your town so if you need to chat, i'm a friendly swell fella & i don't mind lending a hand. Darren. thumbs up

Chrome Dinette · Posted: Fri Aug 24, 2012 6:15 am Post subject:

Yeah, Sprague Atoms are nothing special for too much money. Also, they are huge compared to other caps of the same value and voltage rating.

equalpyramid · Posted: Fri Aug 24, 2012 7:08 pm Post subject:

metasonix · Posted: Fri Aug 24, 2012 10:06 pm Post subject:

equalpyramid · Posted: Mon May 06, 2013 7:33 pm Post subject:

Update!

The restoration was very successful. Works like a charm and overdrives as well as any 12AX7-based circuits. I fucking love this thing. Simple things become complex and buzzy. I strongly recommend them.

Moog$FooL$ · Posted: Mon May 06, 2013 11:19 pm Post subject:

ah yes..... one of those came in to NJAMS when i use to work there.
good for you. thumbs up

were the 6sc7 in their when u got it? or did u buy some new olds??

equalpyramid · Posted: Tue May 07, 2013 12:58 am Post subject:

I got a full set of NOS, but will hold onto the original ones until I can test them (won't mind having spares). Checked for a difference in sound between GE's metal and Tung-Sol's glass 6sc7's, so far they are pretty damn close, but will investigate more later. I'll do my best to get a demo up to.

zerosum · Posted: Tue May 07, 2013 6:10 am Post subject:

Octal tubes are so pretty! love