The JTM45 should be very loud. If all else fails, check for an incorrect component value. Specifically, I'd check all the resistors. Look for, for example, you used 100K where you need a 1K or something on that order. To do this, use the schematic. Check twice. Once from right to left and then a second time from left to right. Mark off each resistor as you check it with a meter. Not all resistors will meter correctly while in circuit due to the way they might interact with the next resistor. So, you also need to verify the stripe codes.
Common problems to look for:
-Something miswired.
-Wrong value resistor likely by a factor of 10x.
-Cold solder.
jtm 45 build issues
Moderators: pompeiisneaks, Colossal
- Reeltarded
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Re: jtm 45 build issues
Particularly the PI
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
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Re: jtm 45 build issues
Finally got some time to sit down and work on the amp, as per tube depots recommendation, I replaced the filter caps( even though I knew they tested fine, which they did once tested after removal)
Rechecked for any off value resistors or caps and re flowed most of the connections on the amp incase of a cold
Solder, check continuity on the connections under the board and still cannot seem to get the amp to sound right.
Planning to go back again to recheck resistors incase I missed something
Rechecked for any off value resistors or caps and re flowed most of the connections on the amp incase of a cold
Solder, check continuity on the connections under the board and still cannot seem to get the amp to sound right.
Planning to go back again to recheck resistors incase I missed something
- statorvane
- Posts: 557
- Joined: Thu May 11, 2006 3:28 pm
- Location: Upstate New York
Re: jtm 45 build issues
Hopefully this will help. I have had trouble on more than one occasion where I had a 470K resistor in place of a 470R resistor at the PI cathode. This resulted in a very low volume sound. Might be worth a check there.
I really hope you find the issue. JTM45s are awesome sounding amplifiers.
I really hope you find the issue. JTM45s are awesome sounding amplifiers.