Hi all
I have been using T-amp for some time and I am very happy with it. But after doing the input mod (2uF paper in oil) my amp gets too loud too soon. I’m using the stock pot (50K). There no more smooth increase in loudness. My amp gets from silent (7 o’clock) to pretty loud (9 o’clock) and then slowly increases volume in the remaining travel. I’ve tried 2 stock T-amp pots and it’s the same thing. How do I fix this? Other value of pot (20k,100k) ? Or put a resistor somewhere? I removed R01 and R02 in stealth mod, so maybe that’s the problem?
I have been using T-amp for some time and I am very happy with it. But after doing the input mod (2uF paper in oil) my amp gets too loud too soon. I’m using the stock pot (50K). There no more smooth increase in loudness. My amp gets from silent (7 o’clock) to pretty loud (9 o’clock) and then slowly increases volume in the remaining travel. I’ve tried 2 stock T-amp pots and it’s the same thing. How do I fix this? Other value of pot (20k,100k) ? Or put a resistor somewhere? I removed R01 and R02 in stealth mod, so maybe that’s the problem?
and a pic. Be gentle it's my first soldering job.
What I can say from the picture and the schema - you have just added extra caps in series to existing caps placed on the sonic impact board - this cant bring you any bass benefit, you gotta replace those onboard stock caps - which is a pretty tedious work since they are ver very small and the copper traces below the get destroyed pretty easily
Thanks for the photo and the schema. At 1st glance, all looks good. I'll do a little double checking later.
The problem you describe often comes when there is no ground to the center of the pot. The pot works as a voltage divider, dividing off your signal to ground. Without a ground connection, it can't do its dividing job, it just becomes a variable resistance in the path of the signal.
Your ground connections are the 1st thing to check. I suspect the problem lies there.
The other thing might be that you've got the pot wired backwards. Check that, too
BTW, are those SAFCO caps you've got there?
The problem you describe often comes when there is no ground to the center of the pot. The pot works as a voltage divider, dividing off your signal to ground. Without a ground connection, it can't do its dividing job, it just becomes a variable resistance in the path of the signal.
Your ground connections are the 1st thing to check. I suspect the problem lies there.
The other thing might be that you've got the pot wired backwards. Check that, too
BTW, are those SAFCO caps you've got there?
panomaniac said:
Thanks for your insight. I'll try wiring the pot the other way around, and then check the ground. I'm new to all of this, how can I check my ground with a multimeter to see if everything is ok?
Don't know what SAFCO is. These are Russian papers in oil, taken from an old medical instrument. I bough them from a guy who took the thing apart and was selling some tubes and caps. Here is a photo of one.
Attachments
Thanks for the photo of the can.
SIC/SAFCO is a French capacitor maker who makes (or made) very nice paper in oil caps. They look a lot like your Rusky caps.
Your soldering looks suspect. You probabaly have a bad solder joint on the ground wire.
To test: Set the volume at a reasonable level, like 7:00~9:00. Play some music. Wiggle the wires. If the ground is bad, but makes contact when you wiggle it, the sound level will drop, but not go away.
SIC/SAFCO is a French capacitor maker who makes (or made) very nice paper in oil caps. They look a lot like your Rusky caps.
Your soldering looks suspect. You probabaly have a bad solder joint on the ground wire.
To test: Set the volume at a reasonable level, like 7:00~9:00. Play some music. Wiggle the wires. If the ground is bad, but makes contact when you wiggle it, the sound level will drop, but not go away.
or the 
smilie to confirm.- Status
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