Author Topic: My New Don Sachs Model 2 Preamp Unboxing  (Read 2084 times)

Offline P.I.

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Re: My New Don Sachs Model 2 Preamp Unboxing
« Reply #45 on: July 21, 2020, 10:27:48 PM »
That is one reason my amp and the integrated amp are auto biasing:)    You can use any 4 output tubes and unless a tube is so far outside any normal bias range the amp really doesn't care and will happily bias 4 wildly different tubes.   So far I have never seen any tube either amp will not bias, but there is probably one out there somewhere.  So you don't have to pay tons for matched quads of tubes that are often all over the map when you buy 10 or 12 of them... like the 6P3S-E.  Or you have to pay someone considerably more for matching them correctly.  I remember the days of finding a single tube to go with three vintage tubes in a vintage amp.... there was always one tube that would never bias hot enough, and another that was too hot.   You never want to be at the limit of a bias pot in any direction.
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Offline doug s.

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Re: My New Don Sachs Model 2 Preamp Unboxing
« Reply #46 on: July 21, 2020, 10:49:11 PM »
my mesa baron does allow for adjustment of bias & balance, but yes, it's nice to have the tubes close, to start.  yes, according to the one seller i mentioned, a pair of matched sextets at $200 total, is ~25-30% more than if i just bought 12 tubes.  but still a reasonable price, imo.  i guess i could buy 4 or five quads to make sure i get 12 that are close, instead of getting the specially matched sextets and have extra spares.  but honestly, even at $200, i think it's a freaking bargain to be able to retube this amp w/such great tubes.

an injury has meant i've been spending much time in the living room on a hella-comfortable big sofa, w/the main system and the baron being on 24/7 for 11 days now.  and, while i've checked the balance/bias twice w/the easy to read switch & meters, no adjustment has been needed.

doug s.
That is one reason my amp and the integrated amp are auto biasing:)    You can use any 4 output tubes and unless a tube is so far outside any normal bias range the amp really doesn't care and will happily bias 4 wildly different tubes.   So far I have never seen any tube either amp will not bias, but there is probably one out there somewhere.  So you don't have to pay tons for matched quads of tubes that are often all over the map when you buy 10 or 12 of them... like the 6P3S-E.  Or you have to pay someone considerably more for matching them correctly.  I remember the days of finding a single tube to go with three vintage tubes in a vintage amp.... there was always one tube that would never bias hot enough, and another that was too hot.   You never want to be at the limit of a bias pot in any direction.

Offline Nick B

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Re: My New Don Sachs Model 2 Preamp Unboxing
« Reply #47 on: July 21, 2020, 11:33:55 PM »
Feel better, Doug. Thatís what I did after surgery. Probably had my McCormack amp.
my mesa baron does allow for adjustment of bias & balance, but yes, it's nice to have the tubes close, to start.  yes, according to the one seller i mentioned, a pair of matched sextets at $200 total, is ~25-30% more than if i just bought 12 tubes.  but still a reasonable price, imo.  i guess i could buy 4 or five quads to make sure i get 12 that are close, instead of getting the specially matched sextets and have extra spares.  but honestly, even at $200, i think it's a freaking bargain to be able to retube this amp w/such great tubes.

an injury has meant i've been spending much time in the living room on a hella-comfortable big sofa, w/the main system and the baron being on 24/7 for 11 days now.  and, while i've checked the balance/bias twice w/the easy to read switch & meters, no adjustment has been needed.

doug s.
That is one reason my amp and the integrated amp are auto biasing:)    You can use any 4 output tubes and unless a tube is so far outside any normal bias range the amp really doesn't care and will happily bias 4 wildly different tubes.   So far I have never seen any tube either amp will not bias, but there is probably one out there somewhere.  So you don't have to pay tons for matched quads of tubes that are often all over the map when you buy 10 or 12 of them... like the 6P3S-E.  Or you have to pay someone considerably more for matching them correctly.  I remember the days of finding a single tube to go with three vintage tubes in a vintage amp.... there was always one tube that would never bias hot enough, and another that was too hot.   You never want to be at the limit of a bias pot in any direction.
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Offline doug s.

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Re: My New Don Sachs Model 2 Preamp Unboxing
« Reply #48 on: July 21, 2020, 11:49:22 PM »
thanks, nick.  it's slow, but i'm doing a bit better.  severely sprained and bruised ankle and lower leg.  fortunately nothing broken.
 i'm able to use a cane now, instead of crutches.  and the ankle, while still a bit fat, doesn't look nearly as fat as it did even 4 days ago. a "half-cast" splint and tight ace bandage wrap really helped.

this time next week, i should be able to go lawn surfing; the yard has gotten totally out of hand.  pics are from the last mow, a month ago:


doug s.

Feel better, Doug. Thatís what I did after surgery. Probably had my McCormack amp.
my mesa baron does allow for adjustment of bias & balance, but yes, it's nice to have the tubes close, to start.  yes, according to the one seller i mentioned, a pair of matched sextets at $200 total, is ~25-30% more than if i just bought 12 tubes.  but still a reasonable price, imo.  i guess i could buy 4 or five quads to make sure i get 12 that are close, instead of getting the specially matched sextets and have extra spares.  but honestly, even at $200, i think it's a freaking bargain to be able to retube this amp w/such great tubes.

an injury has meant i've been spending much time in the living room on a hella-comfortable big sofa, w/the main system and the baron being on 24/7 for 11 days now.  and, while i've checked the balance/bias twice w/the easy to read switch & meters, no adjustment has been needed.

doug s.
That is one reason my amp and the integrated amp are auto biasing:)    You can use any 4 output tubes and unless a tube is so far outside any normal bias range the amp really doesn't care and will happily bias 4 wildly different tubes.   So far I have never seen any tube either amp will not bias, but there is probably one out there somewhere.  So you don't have to pay tons for matched quads of tubes that are often all over the map when you buy 10 or 12 of them... like the 6P3S-E.  Or you have to pay someone considerably more for matching them correctly.  I remember the days of finding a single tube to go with three vintage tubes in a vintage amp.... there was always one tube that would never bias hot enough, and another that was too hot.   You never want to be at the limit of a bias pot in any direction.