Pics of my SIR 39 copy (AFAIK!)
- neikeel
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Re: Pics of my SIR 39 copy (AFAIK!)
Since those pics I did a rewire for V1b to be stock 1959 to '69 specs that I wanted and then V0b to V0a being 2203 and V1a as the extra stage. This gives a pretty good warmed up 2203 approximation, the 4 stager is not bad but does seem sensitive to speaker cab choice. I plan to leave it alone for the moment as other fish to fry. I have other ideas but will try them later when I get my 50watt 4-stager going (probably next year at this rate!). I want to experiment more with adjustable NFB instead of resonance which only really seems to make a big difference with the amp fully cranked and breathing deeply, which of course is almost impossible, even the use of an attenuator affects it too.
Neil
- Jeremy1283
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Re: Pics of my SIR 39 copy (AFAIK!)
Nice work!
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Re: Pics of my SIR 39 copy (AFAIK!)
Hi
. What a very nice, and clean build.
Love how you went with nos parts. I love nos stuff myself. I personally know Frank Levi, and will send him this thread to check out your pics of your cool amp. Bet he'd like to see these pics
. He told me one guy completely reversed engineered on of the old Sir amps that Slash used.




- herbvis
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Re: Pics of my SIR 39 copy (AFAIK!)
rockdude1 wrote:Hi. What a very nice, and clean build.
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Love how you went with nos parts. I love nos stuff myself. I personally know Frank Levi, and will send him this thread to check out your pics of your cool amp. Bet he'd like to see these pics
. He told me one guy completely reversed engineered on of the old Sir amps that Slash used.
Hi rockdude1, Welcome to the forum

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Re: Pics of my SIR 39 copy (AFAIK!)
Hi, thank you for the welcome
. He's had a cold but doing well
. Spoke to him on the phone today, and he was getting better
. I haven't checked out that section yet but will. We are working on a prototype for one of his designs now
. I feel blessed because i'm the only one who has got to see the Design. It's an amp Doug Aldrich used with Bad Moon Rising that was modded. I'm a big Aldrich fan, love his old band Lion. This amp will use his choice of components, he will be giving it a name. The economy being so unpredictable I hope we can build at least 1 dozen amps. We are working on a really good price point for this amp so it won't have a big expensive price sticker. I will be assembling them for him
.





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Re: Pics of my SIR 39 copy (AFAIK!)
Beautiful amp Neikeel! I have been playing around with adjustable NFB myself and recently discovered that I really enjoy the sound with the NFB disconnected. I am using a switch to go between 100k/8ohm and zero NFB but I am leaning towards using a pot to give more options.
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- Location: Lake Stevens Washington
Re: Pics of my SIR 39 copy (AFAIK!)
You will find you like the pot for this reason, depending on parts including speakers and pick ups each amp has a sweet spot .
I use it as a tweeking point on every amp now. I find the spot take it out and measure replace it with a resister then no more pot needed.
Bill
I use it as a tweeking point on every amp now. I find the spot take it out and measure replace it with a resister then no more pot needed.
Bill
- jerrydyer
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Re: Pics of my SIR 39 copy (AFAIK!)
I likes it



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