The 8084 is a really beautifull pre-amp. When I compare it to the specs given by other kits
But why we don’t go further in upgrading this beautifull pre-amp!
An upgrade is done by moving a low-class opamp to a better one with much better specs. (take a look at differences in schematics and povided IC…you will see the difference).
But why we can’t go further. I really don’t know if it makes any difference. Money talks in kits I think.
Anyone tried to chance the ceramics caps by some WIMA’s?
does it worth the exchange?
Does the K8084 need better transformer if the ICs are changed to OPA 2604 AP’s. I am using a 300mA transformer for two K8084’s, but I just changed the chips so I need to know…
Okay, so I went out and tried this. First everything seemed to work okay, but then I started hearing some weird noise where my transformers was, and I noticed that the 2x12V 50W transformer, which I use for the K4003, thats controlled with the K8084 had started to heat and ALOT… Btw I have also changed transistors BC547 to 2N 2222A and BC557 to 2N3906, on the K8084. Im not sure, that the heating of the K4003’s transformer is caused by the K8084 upgrade, but I ordered an 2x18V 120W transformer and will check how that works…
Another question: I am now using a 7,2VA 2x12V 300mA transformer for two upgraded K8084’s, should that be enough? I havent seen any heating from it yet, but I havent kept them on because of the problem I am having with the heating transformer of K4003.
[quote=“Lillerinmuna”]Okay, so I went out and tried this. First everything seemed to work okay, but then I started hearing some weird noise where my transformers was, and I noticed that the 2x12V 50W transformer, which I use for the K4003, thats controlled with the K8084 had started to heat and ALOT… Btw I have also changed transistors BC547 to 2N 2222A and BC557 to 2N3906, on the K8084. Im not sure, that the heating of the K4003’s transformer is caused by the K8084 upgrade, but I ordered an 2x18V 120W transformer and will check how that works…
Another question: I am now using a 7,2VA 2x12V 300mA transformer for two upgraded K8084’s, should that be enough? I havent seen any heating from it yet, but I havent kept them on because of the problem I am having with the heating transformer of K4003.
-Rest in peace Randy Savage.[/quote]
Okay, the transformer heating wasn’t because of the opamp upgrade, it was caused by broken IC on the K4003, probably cause I has banged the chasing nearby with a hammer… Now works fine.
