TSL122 100 to 50 watt

ivanppg

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Hey, i'm gonna get the tubes. But for now I did 0xx0 placement (outer inserted). One bias pin set to 35mV, other one gives 0mV. 16ohm speakers in the 8ohm output.
Is it right? :D
I think i'm gonna get rid of this TSL anyway.
Do hotter bias as 85mV per side (with 4 good tubes) will give more warm and less fizzy sound than the very cold like 45mV?
 

Dogs of Doom

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the recommended (by Marshall) of 90mV/side was way too high. Many people like it around 72/side...

if you have 1 tube per side, divide by 2...

so,

72/2=36/side
80/2=40/side

etc...

then make load adj., as stated above...
 

ivanppg

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the recommended (by Marshall) of 90mV/side was way too high. Many people like it around 72/side...

if you have 1 tube per side, divide by 2...

so,

72/2=36/side
80/2=40/side

etc...

then make load adj., as stated above...
What does It mean a "side" :D
I have 2 tubes going 0xx0. Left pin is 0mV, right pin is 35mV.
Should I move the tube to balance It and set 35mV each pin, or run It as it is? Seems like my right pin is for outter tubes and the left one is for inner.
 

Dogs of Doom

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that's what I was saying before. put the tubes in x0x0 or 0x0x, then bias it. Yeah, it should be balanced, like 35/side... or more, but, I wouldn't go over 40...

you have 3 pins. center pin is ground. Then you have a left/right pin. balance the left/right sides...

if one side is reading 0mV, you may have other problems... are you using a multi-meter? or a bias tool?
 

ivanppg

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that's what I was saying before. put the tubes in x0x0 or 0x0x, then bias it. Yeah, it should be balanced, like 35/side... or more, but, I wouldn't go over 40...

you have 3 pins. center pin is ground. Then you have a left/right pin. balance the left/right sides...

if one side is reading 0mV, you may have other problems... are you using a multi-meter? or a bias tool?
Ahh, one says 0xx0 one say 0x0x...
Im confused, i did 0xx0, that's why i have voltage on only one pin...
I use multimeter and pins on the back of the amp. Now it's clear, will try It tommorow. Thanks man!
 

Pete Farrington

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other one gives 0mV. …
Is it right?
There’s a fault.
Either the valve or the circuit around that socket, related to that reading, is bad.
The amp will sound horrible.
one says 0xx0 one say 0x0x...

Either should give the same result. If they don’t, there’s a fault in the amp, with the circuit related to that socket.
 
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Dr.Twang!

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Should I move the tube to balance It and set 35mV each pin, or run It as it is? Seems like my right pin is for outter tubes and the left one is for inner.
The 2 left tubes are connected together and to the left pin
The 2 right tubes are connected together and to the right
The center pin is connected to chassis ground.
 

Jethro Rocker

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Even running

Hey, i'm gonna get the tubes. But for now I did 0xx0 placement (outer inserted). One bias pin set to 35mV, other one gives 0mV. 16ohm speakers in the 8ohm output.
Is it right? :D
I think i'm gonna get rid of this TSL anyway.
Do hotter bias as 85mV per side (with 4 good tubes) will give more warm and less fizzy sound than the very cold like 45mV?

I think because you placed tubes in outer sockets only 1 pin will read if I recall.
45 is way to cold for 2 tubes. It will lose some fizz if you get it higher. I have mine around 84 for a pair, I like it tonally better than 78 for the pair. I like more modern saturation.
One of my favorite sounding amps.
that's what I was saying before. put the tubes in x0x0 or 0x0x, then bias it. Yeah, it should be balanced, like 35/side... or more, but, I wouldn't go over 40...

you have 3 pins. center pin is ground. Then you have a left/right pin. balance the left/right sides...

if one side is reading 0mV, you may have other problems... are you using a multi-meter? or a bias tool?
That could be, I can't recall if it is per side or per side of AB push pull...
I like mine just over 40 per tube.
 

Jethro Rocker

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The pair of sockets on the left share a cathode current sensing resistor, likewise the pair of sockets on the right.
As per post #27.
Ah so Left pin is left side right pin is right side. I couldn't recall amd wasn't sure which was correct. I missed some posts too it seems.
Yes he would have an issue. May have another dead tube.?
 


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