This is all I have for ITAM
Type: Posts; User: dmeek; Keyword(s):
This is all I have for ITAM
I go for the Rustic/Homemade effect. In other words I'm too cheap to buy one.
Yes, that's a more accurate way to put it. My equation only applies when both capacitors are the same value as they are in this case.
Maybe Bipolars were more expensive. The thing to remember is that two caps in series of equal value will become half the value of one. The voltage rating will be unchanged.
Somehow there must be a...
Here it is in schematic form. I'm not sure we know the value of the caps yet. Whatever they are, the bipolar cap should be half the value marked on one of the originals Or just use 2 caps...
When you get the boards out look closely at all jumper wire connections between boards, the solder often cracks there. Also re-solder all the tube sockets. I've also had trouble with filament...
As I remember it the problem with aluminum wire is that it is too soft, will squash under a screw and loosen easily, then arc over and burn your house down, whereas copper has a bit of springyness...
If I ever see a brown spot on a molex socket used for a heater connection I hardwire the two wires. End of story. No need to measure anything.
The leads on these are flat. I'd like to see the datasheet but that seems highly unlikely
R144 is 220 ohms/ 2 Watt
On the newer version schematic they use 2SC373 in place of the 25H. I ended up using 2SC1000. The 25H was making a lot of noise. Now on to fixing the tremolo and reverb
Thanks g1, I have those and other old Yamaha schematics. No luck. Looking in some of my old books it looks like the C401 is indeed 2SC401 made by Sony. There is also a
2SC293 on the board, a TO5...
I'm working on an old TA-30, seems to be an earlier version than the schematics that are available, ser #20049 pcb #LC-0400-2.
I'm curious about the transistors, I can't find data anywhere. they are...
A friend brought me a non-working U87 a while back. Like Mick I didn't want to touch the capsule. It's always been the point where I would give up on a mike. This one was visibly grimey and I figured...
This might be getting a little off-topic but I've never used a light bulb for limiting. What always bothered me is that I would like to know how much
current I'm allowing. With the non-linear...
And here's the Wiring
Here is the RP amp. I also have the overall wiring diagram, I'll scan that tomorrow.
I had the ST-3, maybe an earlier version. For all I know I might still have it, stuffed away in some corner, knowing how I hate to throw anything out.
Years ago at an auction I bought a Strobotuner 6T for dirt cheap. It had a 2X6L6 amplifier driving a tuning fork for the frequency standard.
Unfortunately when I got it home I found the compartment...
I thought the idea was to mass produce "tubes" cheaply using existing flourescent display technology. If it's costing $60 plus for a low quality tube I predict they will disappear soon.
This may be the schematic (reverse engineered). I don't remember where I found it.
There is some discussion about it in this thread https://el34world.com/Forum/index.php?topic=12201.0 A shorted SIDAC will cause hum.
Here is a SIDAC datasheet
Maybe the same as this one
The power switch controls the standby/mute on the TDA7294
Some time ago I had a keyboard with an intermittent PCB. The problem was a cracked via, completely invisible but easy to find by tracing the signal.
In this case, with everything inside a feedback...
At least if you still have noise with the output stage out of the circuit. it will be narrow the search down. You could short out Q4 and Q5 too
At some point when as much as possible has been...
You've run into the same problem I had in trying to isolate the source of the noise https://music-electronics-forum.com/showthread.php?t=50083.
I finally gave up on it, but I think your idea of...