Tube change - Vox Lil Night Train

[Benjamin Hwang]

Hello everyone,

I am thinking of replacing the original china 12AX7 with a JJ Tesla 12AT7 in the V2 (preamp and Phase Inverter) section, because i find the gain the Lil night train a little bit too bright and too much gain. Would that require re-biasing?

Original setup is 12AX7s in V1 and V2, and a 12AU7 in V3

From forums ive heard that 12AT7 will tame down the gain a little which is what im looking for, since i get my distortion from my pedals. I am also getting a JJ tesla 12AX7 (V1) and 12AU7 gold pin (V3 output) for the tube change. Would this setup be recommended?

Thank you for reading

 

[CyanideJunkie]

I would think that a 12AY7 in V1 would do the most good in cleaning up your signal. A rebias shouldn't be required nonetheless.

 

[Benjamin Hwang]

What about 2 5751s? Im afraid the 12AY7 will clean up too much

 

[CyanideJunkie]

That might work. It's all a matter of personal taste in the end.

Just remember that in the end, the Lil' NT is a 2-watt amp designed for crunch tones so getting nice clean tones from it might be tricky.

 

[Benjamin Hwang]

My main concern is that the amp should be clean enough to handle distortion pedals, thats what im looking for. The sound now with 12AX7s still seem abit too harsh with my distortion pedals on.

 

[zesn]

Have experienced what you felt, harsh sounding.

Though changing the tubes might work, the amp might still retain some part of its harsh character

 

[CyanideJunkie]

My main concern is that the amp should be clean enough to handle distortion pedals, thats what im looking for. The sound now with 12AX7s still seem abit too harsh with my distortion pedals on.

That's due to crossover distortion. Your distortion pedal is basically distorting an already distorted preamp signal. A 5751 is the next step down from a 12AX7 in terms of gain factor, so it will tame things a little. A lower value tube in your PI will help to clean things up as well. Whether or not it's clean enough to mate well with your distortion pedals will depend on your gear and ears.

 

[Benjamin Hwang]

The amp is already quite clean when i disengage the pedal, but it seems like the amps distortion will come in and mix together with my pedal's distortion and I activate it.

I am thinking of clipping the C19 capacitor as forums mentioned it tames down the treble quite a big lot, but I am afraid of taking that risk since I dont know how to solder it back incase if it isnt what I like

 

[CyanideJunkie]

In that case, stick with trying different tubes for now. Soldering the cap back is easy and any decent tech should know how.

 

[Benjamin Hwang]

Thank you for always replying to my threads! Much appreciated. Waiting for my tubes i ordered online to arrive~

 

[seeyoudownthere]

Wouldn't controlling the level of distortion on the pedals help a lot more?
They're the items pushing your pre & post amp. EQ'ing may help too.