here's my new find. however, i'm torn. i'd reallllly like an rta to play with (car audio nut more than home audio), but i'd also like a matching preamp rack case for my 3 space soon-to-be 6ch gc setup. since the rta is not working right, its kinda making me lean more toward turning the case into a preamp case, but who knows. i can always keep the guts and put em in something later (even easier is that the front and back panels unscrew from the rest of the case)....
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Alot of websites to look at
hi some of this stuff has been listed but i had alot of extra sites on my favorities list
heres the link
-chrishttp://www.angelfire.com/alt2/pic60237/
Anything you see here use at you own risk. And i have not bought parts from all these people so check it out first.
-chris
hi some of this stuff has been listed but i had alot of extra sites on my favorities list
heres the link
-chrishttp://www.angelfire.com/alt2/pic60237/
Anything you see here use at you own risk. And i have not bought parts from all these people so check it out first.
-chris
OK!!! got my 50k pots from Bridger.
The ones I had mentioned early in this thread.
A very interesting thing is that they consist of SIX wafers.
So, there are (4) 50k pots and (2) 2k
If you just wire 2 of the wafers in parallel for each channel
you will have the optimal 25k gainclone pot without even using a faking resistor in parallel (which might make them a bit too log, because they are audio taper already)
I don't know what the opinion is on paralleling them this way is, but I can seee more advantages than disadvantages, better tracking, maybe, more wipers making contact....
The 2k decks are of course meant to be used as a balance control
They are connected to the brass outer sleeve have a center detent, and it is tempting to impliment a balance function, at the risk of offending purists...
Anyway, at $2 they appear to be my best find.
I got one motorized one, and it has (4) 50k decks
The ones I had mentioned early in this thread.
A very interesting thing is that they consist of SIX wafers.
So, there are (4) 50k pots and (2) 2k
If you just wire 2 of the wafers in parallel for each channel
you will have the optimal 25k gainclone pot without even using a faking resistor in parallel (which might make them a bit too log, because they are audio taper already)
I don't know what the opinion is on paralleling them this way is, but I can seee more advantages than disadvantages, better tracking, maybe, more wipers making contact....
The 2k decks are of course meant to be used as a balance control
They are connected to the brass outer sleeve have a center detent, and it is tempting to impliment a balance function, at the risk of offending purists...
Anyway, at $2 they appear to be my best find.
I got one motorized one, and it has (4) 50k decks
Hey Variac,
How does it sound? Have you hooked up the pot yet? I ended up ordering a Piher dual 10K audio pot from Mouser.com with some other bits. I'll get them tomorrow or the next day, but I still have to finish off a pair of speakers before I can get building. I'm still not sure what I'll use as a final volume control, but the Piher should work in the short-term. The only thing I'm missing are the speaker connects--I'm planning on stopping by RS and picking up a pair--Mouser didn't have anything nice.
Cheers,
Bret Morrow
How does it sound? Have you hooked up the pot yet? I ended up ordering a Piher dual 10K audio pot from Mouser.com with some other bits. I'll get them tomorrow or the next day, but I still have to finish off a pair of speakers before I can get building. I'm still not sure what I'll use as a final volume control, but the Piher should work in the short-term. The only thing I'm missing are the speaker connects--I'm planning on stopping by RS and picking up a pair--Mouser didn't have anything nice.
Cheers,
Bret Morrow
Nothing hooked up yet. For speaker terminals I had a friend add a bunch of black and red plastic ones to his order to Parts Express. Absolutely nothing special about them except that they look really sturdy, and they had to be cheap, or I would have been better off ordering the Cardas patent ones. I couldn't afford a bunch of those, so will go loball on terminals for now and hopefully have less projects going at once next year when the Cardas group order comes along.
Ok, I promised a book report, er BOX report on the par metal box I ordered.
I ordered the 20-12083BM Which means the 20 series, 12" wide,
8" deep from front to back, and 3" high.
BM I think means blackfrontplate and black box paint, but I'm not sure it also indicates that I ordered a 3/16" thick black front plate. The 3/16" is 50% thicker than the 1/8" stock panel of course, and worth it for a more solid look. This was the thickest they had in stock, even thought they mention 1/4" and 3/8" thick in the online catalog.
The black box with the thick plate is $49.20
a pair of silver handles $ 7.80
$8.25 shipping/handling
TOTAL $65.25
How do I feel about it? Well my first rule was my box had to be less than half the price of Peter's or why bother? There is no doubt his are very very nice. BUT, I think at well less than half, the par-metal is a really good deal.
The 20 series is all aluminum, so should be easy to cut for holes. In the size I got, it is plenty rigid. the screws are machine screws, not sheet metal screws, which was a nice surprise. They screw into threaded cylinders pressed into holes in the box, I think they are called clinch fasteners? This arrangement allows you to tighten them a lot to make the whole thing relly solid and rigid.
As you can see, the inside surfaces are alodined, the outside pant is slightly textured.
I ordered the 20-12083BM Which means the 20 series, 12" wide,
8" deep from front to back, and 3" high.
BM I think means blackfrontplate and black box paint, but I'm not sure it also indicates that I ordered a 3/16" thick black front plate. The 3/16" is 50% thicker than the 1/8" stock panel of course, and worth it for a more solid look. This was the thickest they had in stock, even thought they mention 1/4" and 3/8" thick in the online catalog.
The black box with the thick plate is $49.20
a pair of silver handles $ 7.80
$8.25 shipping/handling
TOTAL $65.25
How do I feel about it? Well my first rule was my box had to be less than half the price of Peter's or why bother? There is no doubt his are very very nice. BUT, I think at well less than half, the par-metal is a really good deal.
The 20 series is all aluminum, so should be easy to cut for holes. In the size I got, it is plenty rigid. the screws are machine screws, not sheet metal screws, which was a nice surprise. They screw into threaded cylinders pressed into holes in the box, I think they are called clinch fasteners? This arrangement allows you to tighten them a lot to make the whole thing relly solid and rigid.
As you can see, the inside surfaces are alodined, the outside pant is slightly textured.
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The box actually looks better than the photos, I would prefer the handles inboard a bit more, which I think I can do by enlarging the holes in the front sheet metal that the handle bolts go through.
That's one of your Indian sample knobs stuck on the front with double sided tape for the photo!
That's one of your Indian sample knobs stuck on the front with double sided tape for the photo!
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In the course of looking for parts, I picked up a
couple of Talema 20/20 5A toroids at Electronic
Dimensions in Tacoma, WA for about $25 apiece.
Glen's got maybe a half dozen more. Plenty of
wire, especially teflon, banana plugs, God only
knows what else. His warehouse is frightening.
http://www.el-dim.com
Doing some more scrounging this weekend. Boeing
Surplus can be a fascinating place to look for odd
blocks of aluminum and even titanium. No telling
what else; it changes from week to week. Got some
very solid office chairs for practically nothing.
No luck so far finding a usable case, but I see some
great ideas here. Maybe I'll get lucky.
For testing purposes, I have a chassis and some
square heatsinks on which I built my first prototype
gainclone. I'll be trying to build a paralleled
version that can be easily swapped in for more
listening tests.
For anyone in the area, I have a very good test
bench oriented towards audio DIY.
couple of Talema 20/20 5A toroids at Electronic
Dimensions in Tacoma, WA for about $25 apiece.
Glen's got maybe a half dozen more. Plenty of
wire, especially teflon, banana plugs, God only
knows what else. His warehouse is frightening.
http://www.el-dim.com
Doing some more scrounging this weekend. Boeing
Surplus can be a fascinating place to look for odd
blocks of aluminum and even titanium. No telling
what else; it changes from week to week. Got some
very solid office chairs for practically nothing.
No luck so far finding a usable case, but I see some
great ideas here. Maybe I'll get lucky.
For testing purposes, I have a chassis and some
square heatsinks on which I built my first prototype
gainclone. I'll be trying to build a paralleled
version that can be easily swapped in for more
listening tests.
For anyone in the area, I have a very good test
bench oriented towards audio DIY.
About here, but down the page a bit at post #386 Sherman details his success using a center tapped transformer with the dual bridge setup as Brian originally designed it. This opens up your options on surplus transformers as many of them are center tapped.
AND we with center tapped trannies don't want to have to use a single bridge and perhaps affect the sound!
http://www.diyaudio.com/forums/showthread.php?s=&threadid=30815&perpage=15&pagenumber=26
AND we with center tapped trannies don't want to have to use a single bridge and perhaps affect the sound!
http://www.diyaudio.com/forums/showthread.php?s=&threadid=30815&perpage=15&pagenumber=26
Just scored 5 300 VA toroids for $6 CAD each!! They are 40-0-40 but if i wire them for 220 and run them on 110 it will be suitable for my 4 channel gain clone (i knew i was procrastinating on actually wiring everything together for a reason....
toroids 2 x 6 = $12 CAD
chassis $9 CAD
$21 CAD -> approx $15 USD
add another $10 for misc
2 x Brian GT kits @ $55 = $110
so that gives me a 4 channel gainclone for $135 USD or about a buck a watt
dave
toroids 2 x 6 = $12 CAD
chassis $9 CAD
$21 CAD -> approx $15 USD
add another $10 for misc
2 x Brian GT kits @ $55 = $110
so that gives me a 4 channel gainclone for $135 USD or about a buck a watt
dave
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You are quite the Frugalphile (Tm) I wish there were more for the rest of us. While running the primeries on half voltage may cut the VA rating in half (same current capacity in the secondaries, but half voltage) I think there has to be some large additional advantage to the bigger trannie- at the least for short, high outputs, Even using this very strict rating , you would still have 75 va/ ch continuous and. I 'll bet it acts like 150 in the short term!!!! My Son o Zen will use the same half voltage approach.
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