Burned marks made me fondly remember the money I made on some D-60 repairs. D60 prior to the D75 If my memory is correct.
Yes. My driver board is entirely different from my schematic's driver board and the circuitry in the manual's schematic varies in large degrees to...You get the point. If you have a different service manual other than the current offering on the Crown site, then you may have an entirely different perspective than I.burnedfingers said:
Ha Ha. Actually I pulled up a transmissionline cabinet and used it to rest my camera on and I took the shot 4~5 feet away zooming in! It's not easy working in the basement with almost no resources and no light. But it's fun...for now. 😉
Cheers,
Shawn.
P.S. I'm off to go see the Drive By Truckers perform live tonight in Toronto! Can't wait! Small town boys like me can't get enough of that hard driving southern rock.
Attachments
Shawn,
I'm posting this for you since I gave you a bad time before about this amplifier.
If you look hard enough you can always find something good.
Section 4 page 17 4.2 of the Crown service manual.
The power supply is capable of 1KW loading. The power transformer weighing 25lbs is constructed of special grain oriented steel. The main DC supplies are full-wave capacitor input type with heavy duty, chassis heat sinked diodes. Computer grade electrolytics furnish 48 joules of energy storage.
I'm posting this for you since I gave you a bad time before about this amplifier.
If you look hard enough you can always find something good.
Section 4 page 17 4.2 of the Crown service manual.
The power supply is capable of 1KW loading. The power transformer weighing 25lbs is constructed of special grain oriented steel. The main DC supplies are full-wave capacitor input type with heavy duty, chassis heat sinked diodes. Computer grade electrolytics furnish 48 joules of energy storage.
I need the board number. Should be either a 7958 or a 9555. Circuit 9555 was used with Fairfield or RCA 1Bo5 outputs.
Check R107 and R207 will be 3.3k with IC uA749 or 10K with IC uA739
Big differences in parts with different outputs and IC's.
Hi Joe,
Yes, my schematic has notes for all of the above cases. I've even had to modify between versions. If my memory is correct, the RCA's were the slower parts. For new parts you would compensate for the Fairchilds. Or did I get RCA and Fairchild mixed up here?
-Chris
Yes, my schematic has notes for all of the above cases. I've even had to modify between versions. If my memory is correct, the RCA's were the slower parts. For new parts you would compensate for the Fairchilds. Or did I get RCA and Fairchild mixed up here?
-Chris
Chris,
The Fairfields and RCA's were slower I believe if memory serves. The 2n3773's can be used in place of them by changing C113,213, and C107, and 207. The 2N3773's were NPC.
This is going back to 1973 so I could be wrong. I will have to read thru some notes from back then.
Chris,
After looking at the schematic would you agree that changing the op amp would be pretty straight forward? I think that even a 5534 would bring on a sonic improvement.
After looking at the schematic would you agree that changing the op amp would be pretty straight forward? I think that even a 5534 would bring on a sonic improvement.
Re: Re: NSD128 - NTE128 -
trannys from left to right : 2n6175, d40p3, d40 p3, crown 151.
krmaudio said:
trannys from left to right : 2n6175, d40p3, d40 p3, crown 151.
Re: NSD128 - NTE128 -
looks like some of your 2961 small signal trannys, (the ones with the green dots on) have been replaced with a later version, like the one where the burnt board is on your picture, (these are as i remember current parts from crown) the pin outs are totally different though, bear that in mind. you should have no problems getting 2n4125 and mpsa 92/ 93....
TomWaits said:
looks like some of your 2961 small signal trannys, (the ones with the green dots on) have been replaced with a later version, like the one where the burnt board is on your picture, (these are as i remember current parts from crown) the pin outs are totally different though, bear that in mind. you should have no problems getting 2n4125 and mpsa 92/ 93....
Hi Joe,
Thanks. That was a very long time ago, and I was but a young lad.
My point was that those compensation components need attention when installing new parts.
Also, for the op amp I think you mean 5532. Remove the pull down resistors.
-Chris
Thanks. That was a very long time ago, and I was but a young lad.
My point was that those compensation components need attention when installing new parts.
Also, for the op amp I think you mean 5532. Remove the pull down resistors.
-Chris
