Wondering if anyone has a Blackcat model 30 R schematic they would care to share or I could purchase a copy of. I contacted the factory and found them to be rude and not willing to help out schematic wise and I don't have the time to draw it out. I'm not a musician and I'm simply trying to help out my church with a labor free repair that I could do. I have it working correctly I believe but would feel better if I could take voltage readings and compare them with good known readings. It passes a good sine wave and produces power ok. This particular model was made in 2008.
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Maybe this will help.
https://www.google.co.uk/search?q=B...=kOQ2WIaDNMPNgAautLqABg#imgrc=EzE7QKWYPnSynM:
https://www.google.co.uk/search?q=B...=kOQ2WIaDNMPNgAautLqABg#imgrc=EzE7QKWYPnSynM:
http://bmamps.com/Schematics/badcat/BadCat_30R_dc30.pdf
Most guitar amp schematics don't include a lot of voltages.
If it works, stop fixing it.
Most guitar amp schematics don't include a lot of voltages.
If it works, stop fixing it.
FWIW.
The Badcat output is actually 2 x EL34, cathode biased with a 270 Ohm 5 Watt resistor, bypassed by a large'ish 220uF on EACH EL34 cathode. Output Tranny Raa is 3K4 and B+ is 375 to 385V.
This produces 32Watts just bellow clipping. The conservative B+ actually makes the amp sound quite effortless. I really like EL34 at this operating point. The cork Sniffer HiFI types will say use a 470 Ohm common screen resistor but any guitar amp which will be overdriven should have separate screen resistors on he output tubes and for EL34 1K 5W is recommended. That is what the Badcat used and what I copied.
I used this arrangement exactly in a Trainwreck clone. Was great with 6CA7 too.
Cheers,
Ian
The Badcat output is actually 2 x EL34, cathode biased with a 270 Ohm 5 Watt resistor, bypassed by a large'ish 220uF on EACH EL34 cathode. Output Tranny Raa is 3K4 and B+ is 375 to 385V.
This produces 32Watts just bellow clipping. The conservative B+ actually makes the amp sound quite effortless. I really like EL34 at this operating point. The cork Sniffer HiFI types will say use a 470 Ohm common screen resistor but any guitar amp which will be overdriven should have separate screen resistors on he output tubes and for EL34 1K 5W is recommended. That is what the Badcat used and what I copied.
I used this arrangement exactly in a Trainwreck clone. Was great with 6CA7 too.
Cheers,
Ian
This Badcat is actually (4) El84's not EL34's. It has a total of (6) 12AX7's, (1) EF86, (4) EL84's and one 5Ar4. This one has a 06 build date.
http://bmamps.com/Schematics/badcat/BadCat_30R_dc30.pdf
This comes really close to the output section. The difference is the schematic listed uses a switch to change the cathode resistor value for the output tubes. The amp I have on my bench uses the 1/2 power full power switch to simply connect or disconnect a 120 ohm cathode resistor to the outside pair of tubes. In the 1/2 power mode the outer pair of EL84's don't have a cathode resistor connection and in the full power mode they have a cathode resistor via the switch.
This comes really close to the output section. The difference is the schematic listed uses a switch to change the cathode resistor value for the output tubes. The amp I have on my bench uses the 1/2 power full power switch to simply connect or disconnect a 120 ohm cathode resistor to the outside pair of tubes. In the 1/2 power mode the outer pair of EL84's don't have a cathode resistor connection and in the full power mode they have a cathode resistor via the switch.
The amp has a separate G2 supply. Would it sound any better taking the 100Ohm resistor directly to the plate supply for each tube?
Define "sound better" 😉
That said, there is a reason for filtering screen supply better than plate supply and that is to avoid supply ripple modulating power output at clipping and creating unmusically related ghost notes, so better leave as is .
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