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#1 |
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diyAudio Editor
Join Date: Dec 2001
Location: San Francisco, USA
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This is a thread to list all the cool stuff you've tracked down to make your Brian GT kit or other gainclone.
****** Ok here's the lamest: Order the Avel Lindburg 330 VA toroid dual 25v secondary from Parts Express: http://www.partsexpress.com/pe/showd...number=122-640 or directly from AV ****** Here's better: Here's some cast cases that would be massive and ribbed enough to function as a GC heatsink: Photo: http://www.fairradio.com/enc-8-6.htm Info: http://www.fairradio.com/cases.htm Ideal enclosures for your next project! All items below are black aluminum chassis with dark grey front panels. The top and bottom of each of the units are heatsinked with 1/10" fins. The overall dimension of each unit is 9 5/8" deep x 5" tall. All enclosures have multiple 1/4" diameter holes on the front plate. They differ according to width. Used excellent. 1 15/16" Wide, 3 lbs sh, #ENC-4-2, $7.50 4 1/8" Wide, 4 lbs sh, #ENC-10-4, $10.00 5 9/16" Wide, 5 lbs sh, #ENC-8-6, $12.00 #### Par Metal Cases: These were already mentioned on the chassis thread, but I just ordered one of the 20 series BUT with a Black anodized front panel, silver small handles, and I got them to increase the thickness of the panel to 3/16" They claim that they can offer up to 3/8" but said on the phone that they couldn't . Still 3/16" is 50% thicker than the 1/8" stock one. For 3"h x 12"w x 8" deep I paid $57 plus shipping. Should look great with the Indian silver knobs. ********* Knobs: Wait till we get the Indian satin silver knob order together: what beauty! and a reasonable price!! If you can't wait 6 or 7 weeks: http://www.apexjr.com/knobs.htm Watch out - the big ones are reallly big! He has transformers often but nine listed that are good gainclone material, BUT some have scored good stuff by calling him be cause he has a few things laying around that he hasn't listed. |
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#2 |
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diyAudio Member
Join Date: Mar 2004
Location: Connecticut
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Most of my finds are from the lab dustbin rather than commerical sources.
1) a 6" x 1.25" x 4" block of aluminum with 2 small, threaded screw holes on the face of it about 4" apart--perfect for the LM3875s. There is also 1 large threaded hole in the center--perfect for mounting it to the case. 2) a 1/2" thick sheet of aluminum that is 3 x 2 feet. It still has its blue plastic on it to protect the polished surface. This 1 isn't quite as useful for this CG, but I couldn'd pass it up (or it would have been pitched out!). that's about it for me, I'm still lost mentally about a volume control. I'm on the learning curve about pots or attenuator or preamps or whatever, now so I'm just thinking of ordering cheap stereo pots from Mouser until I know more. http://www.mouser.com/ I have also been having a grand time playing around with the external design--I'm thinking of something like a over simplified Shinto shrine. Small footprint and more vertical than most designs, but why not? (OK other than heat dissipation) Cheers (& waiting with baited breath for USPS), Bret Morrow |
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#3 |
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diyAudio Editor
Join Date: Dec 2001
Location: San Francisco, USA
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You could cut the 1/2" aluminum with a table saw or chop saw with a non-ferrous metal cutting blade. Peter Daniel does it all the time, that's how he makes his great cases. Now 1/2" ain't gonna resonate a lot and that's good!!
I'm doing the layered tall look on another type amp, so I suspect I basically know what you're up too!!
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#4 |
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diyAudio Member
Join Date: Nov 2002
Location: Lawrence, Kansas, USA
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I was looking at the transformers that Leeds has - 2x18V, 225VA Plitron, but was not sure if it would be beefy enough. I guess I could get two and go dual mono... for $30/trafo, seems like a good deal.
Hmmmm... If I go dual mono, I could build an outboard supply that could be used to power a number of projects: Mini A, A-X, etc. (one at a time, of course). Cody |
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#5 |
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diyAudio Member
Join Date: Nov 2001
Location: Mars
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hi
FWIW, i've built a 6-channel clone using two of the Plitron units (dual mono, each transformer supplies 3 channels). The transformers are great - very beefy units with no buzz/noise issues. With el-cheapo toroids I would be a bit vary of mechanical noise. IMHO, the loose-ish windings found in some of the cheaper toroidals make for a lot of buzzing headaches. HTH- p |
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#6 |
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diyAudio Editor
Join Date: Dec 2001
Location: San Francisco, USA
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I didn't know about Leeds. Here is the transformer:
http://www.leedselect.com/parts.html#transformers I really don't know for sure, but I would agree that they prob will be fine for 2 channels First, beacause they are 18v rather than 25. Second, Pliutrons are rated quite conservatively from what I've heard. |
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#7 |
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diyAudio Member
Join Date: Mar 2004
Location: Connecticut
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Cut'n'pasted from Variac:
You could cut the 1/2" aluminum with a table saw or chop saw with a non-ferrous metal cutting blade. Peter Daniel does it all the time, that's how he makes his great cases. Now 1/2" ain't gonna resonate a lot and that's good!! new from me: I have been looking into that but I think that that will wait until the next CG. The idea of lifting this chunk of metal up on my table saw kinda scares me! Besides, I like to finish this 1st CG sooner rather than later. Of course for me that may mean late summer--my daughter & I are still building a pair of speakers for her that we started last fall. Here is the PartsExpress.com transformer that OfficeBoy posted on the forum. Just in case someone in the BrianGT group buy missed his post, its on the opening page of www.partsexpress.com until 5 PM EST Wednesday. Cheers, Bret Morrow |
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#8 |
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diyAudio Editor
Join Date: Dec 2001
Location: San Francisco, USA
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Those Parts Express trannies look hard to beat- but I've got somethin' that just might. BUT I'm going to order some first to make sure the quality is good enough for you guys. Then once I safely have mine, I'll be happy to post the info (what a jerk I am!)
I also bought a gainclone kit for my kid (son) Instead of building him speakers, I pulled my old Boston Acoustics A70's out of the attic and got a foam surround repair kit from Parts Express to replace the long ago rotted cone surround. I took my time (about an hour) and they are now repaired- and no rubbing of the voice coil!!!!! This repair is about the most rewarding DIY thing I've done- A worthless pair of speakers is now jazzin' out hooked to an old receiver. Wait till he hears the gainclone!! Hey! I need some potentiometers (20k-30K?) who knows of some decent ones at a decent price? Here is thePar-metal case link from my first post: http://www.par-metal.com |
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#9 | |
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diyAudio Member
Join Date: Feb 2003
Location: Somerset, SW England
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Quote:
2 x 80VA is sufficient to produce perfectly good results with a Gainclone. IMHO over 200VA per channel is overkill and a waste of money unless you already have a traffo of that size.
__________________
The truth need not be veiled, for it veils itself from the eyes of the ignorant. |
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#10 | |
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diyAudio Member
Join Date: Mar 2004
Location: Connecticut
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Quote:
The pot is still eluding me. BrianGT is putting together a ladder attenuator group buy over on the bits 'n bobs forum (I think its really called parts & something). Its going to be about $90 which is probably a good buy, but I'm not ready to commit to that yet. I really have been considering just getting a cheap RadioShack replacement stereo pot & using this for a bit until I can decide or 10 years, whichever comes first ! Glad to hear the BA speakers are alive & well. My friend repaired his last year & they are thumping again. I decided not to repair my woofer rot speakers--its more fun to build new ones. Cheers, Bret Morrow |
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