TravAndAlex
Active Member
So I've had a 2215b sitting on a basement shelf for a couple years. Picked it up broken inexpensively because it made no sound. Tested the preamp section by terminating the 3 conductor cable to the amp board to RCA jacks temporarily and all seems well with that half of the equation.
Tested all resistors and they appear to be within range.
Figured I'd just do a reasonably major overhaul of the amplifier board to see if that fixes things. Partial success. It plays but sounds almost as if the gain is too high. Played softly it is reasonably clear, but when turned up the bass is very distorted. Wondering if anyone knows what might be the culprit?
From another thread, here are the replacement transistors I used:
701/702 KSA992FBU
703/704 KSC2690AYS
705/706 KSC1845FTA
707/708 KSC2690AYS
709/710 KSA1220AYS - original thread recommended KSA1220YSTU but as they were not available, the thread suggested the KSA1220AYS as a replacement.
MJE15030 (NPN) for the D313
MJE15031 for the PNP B507D
Details from my order:
2 KSA992FBU-ND TRANS PNP 120V 0.05A TO-92
2 KSC1845FTACT-ND TRANS NPN 120V 0.05A TO-92
4 KSC2690AYSFS-ND TRANS NPN 160V 1.2A TO-126
2 KSA1220AYSFS-ND TRANS PNP 160V 1.2A TO-126
2 MJE15030GOS-ND TRANS NPN 150V 8A TO220AB
2 MJE15031GOS-ND TRANS PNP 150V 8A TO220AB
6 493-11035-1-ND CAP ALUM 100UF 20% 35V RADIAL
2 493-15143-ND CAP ALUM 47UF 20% 50V RADIAL
2 493-3181-ND CAP ALUM 2200UF 20% 35V RADIAL
4 EF1105-ND CAP FILM 1UF 10% 100VDC RADIAL
Before and after pictures:
Tested all resistors and they appear to be within range.
Figured I'd just do a reasonably major overhaul of the amplifier board to see if that fixes things. Partial success. It plays but sounds almost as if the gain is too high. Played softly it is reasonably clear, but when turned up the bass is very distorted. Wondering if anyone knows what might be the culprit?
From another thread, here are the replacement transistors I used:
701/702 KSA992FBU
703/704 KSC2690AYS
705/706 KSC1845FTA
707/708 KSC2690AYS
709/710 KSA1220AYS - original thread recommended KSA1220YSTU but as they were not available, the thread suggested the KSA1220AYS as a replacement.
MJE15030 (NPN) for the D313
MJE15031 for the PNP B507D
Details from my order:
2 KSA992FBU-ND TRANS PNP 120V 0.05A TO-92
2 KSC1845FTACT-ND TRANS NPN 120V 0.05A TO-92
4 KSC2690AYSFS-ND TRANS NPN 160V 1.2A TO-126
2 KSA1220AYSFS-ND TRANS PNP 160V 1.2A TO-126
2 MJE15030GOS-ND TRANS NPN 150V 8A TO220AB
2 MJE15031GOS-ND TRANS PNP 150V 8A TO220AB
6 493-11035-1-ND CAP ALUM 100UF 20% 35V RADIAL
2 493-15143-ND CAP ALUM 47UF 20% 50V RADIAL
2 493-3181-ND CAP ALUM 2200UF 20% 35V RADIAL
4 EF1105-ND CAP FILM 1UF 10% 100VDC RADIAL
Before and after pictures:
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