Hi all
I have a Session Rockette 30watt amp of mid-80s vintage. It's a good little amp, but it's started to get a hum/buzz, too noticeable to record with.
I am thinking that it's the electrolytic caps - is this a likely culprit? If so - is it good idea to replace all the electrolytic caps - there's only 12. This could be cheaper than going to an amp tech, and I am very experienced with a soldering iron so it wouldn't be a problem.
If 'no' - what is more likely the cause of the hum?
If 'yes' - is there a fav brand of caps to use - is it true that Elna Silmic II are the ones to go for? I have sourced them on ebay, though they are not cheap - am I going overboard here, or is there a cheaper brand of cap that will be just as good? For the power supply end I have found some Panasonic FC and FM pairs which are the right spec (note I tried to get all 12 from Panasonic, but there's a few which aren't available in their FC, FM ranges).
And just one more question: at the very input end of the amp circuit, it specs a 1uf 63v electrolytic, but I can't seem to get that as a Panasonic or Elna - so could I use a 2.2uf 63v (or a 1uf 50v) of either of those brands instead, or should I just get another one I found on the web which is this spec:
MCGPR63V105M5X11 Multicomp CAPACITOR, 1UF 63V
Capacitance: 1F
Capacitance Tolerance: 20%
Diameter: 5mm
Lead Spacing: 2mm
Operating Temperature Range: -40C to +85C
Voltage Rating: 63VDC
AC Ripple Current: 12mA
External Length / Height: 11mm
Lead Diameter: 0.5mm
Leakage Current: 16.86A
Operating Lifetime: 2000h
Operating Temperature Max: 85C
Operating Temperature Min: -40C
Package / Case: Radial
Ripple Current Frequency: 120Hz
Ripple Current Temperature: 85C
Terminal Type: Wire Ended
I have attached the schematic for this amp, which I found on the Session website. Note that at the input it has that 1uf 63v electr cap - but could that have been a 2.2uf 63v or a 1uf 50v?
Thanks I hope that's not too many questions at once.
Merry Xmas,
Jim
I have a Session Rockette 30watt amp of mid-80s vintage. It's a good little amp, but it's started to get a hum/buzz, too noticeable to record with.
I am thinking that it's the electrolytic caps - is this a likely culprit? If so - is it good idea to replace all the electrolytic caps - there's only 12. This could be cheaper than going to an amp tech, and I am very experienced with a soldering iron so it wouldn't be a problem.
If 'no' - what is more likely the cause of the hum?
If 'yes' - is there a fav brand of caps to use - is it true that Elna Silmic II are the ones to go for? I have sourced them on ebay, though they are not cheap - am I going overboard here, or is there a cheaper brand of cap that will be just as good? For the power supply end I have found some Panasonic FC and FM pairs which are the right spec (note I tried to get all 12 from Panasonic, but there's a few which aren't available in their FC, FM ranges).
And just one more question: at the very input end of the amp circuit, it specs a 1uf 63v electrolytic, but I can't seem to get that as a Panasonic or Elna - so could I use a 2.2uf 63v (or a 1uf 50v) of either of those brands instead, or should I just get another one I found on the web which is this spec:
MCGPR63V105M5X11 Multicomp CAPACITOR, 1UF 63V
Capacitance: 1F
Capacitance Tolerance: 20%
Diameter: 5mm
Lead Spacing: 2mm
Operating Temperature Range: -40C to +85C
Voltage Rating: 63VDC
AC Ripple Current: 12mA
External Length / Height: 11mm
Lead Diameter: 0.5mm
Leakage Current: 16.86A
Operating Lifetime: 2000h
Operating Temperature Max: 85C
Operating Temperature Min: -40C
Package / Case: Radial
Ripple Current Frequency: 120Hz
Ripple Current Temperature: 85C
Terminal Type: Wire Ended
I have attached the schematic for this amp, which I found on the Session website. Note that at the input it has that 1uf 63v electr cap - but could that have been a 2.2uf 63v or a 1uf 50v?
Thanks I hope that's not too many questions at once.
Merry Xmas,
Jim