Tung-sol 12ax7 in V1 of DR

[stompboxfreak72]

After reading multiple posts about putting a Tungsol in V1 I finally took the plunge ( less than $40 for 2 tubes including shipping ) and hooked up my DR tonight. The sound improvement really is amazing. Channel 3 has way more definition now.

I am not very well versed in the mechanics of amplification but I am really curious as to the role of V1. I realize that it is the input stage preamp tube but there has got to be more to the story as to why this little change in tubes can alter the overall tone so much.

Please gear heads chime in and explain V1.

This is the best improvement in my tone since I bought an Xotic BB preamp after reading about it on this board. I highly recommend the Tungsol in V1 even if I have no idea why the change sounds so much better.

 

[Charlie]

I had a similar experience with my F-50. V1 is pretty much the heart of the preamp - this is where the signal is first amplified and also where your preamp distortion comes from. I'm sure somebody with more technical wits will chime in and give a better explaination but thats the gist of it.

It's similar to changing out pickups on a guitar - it's still going to sound like the same guitar but it will make a big difference in the overall tone.

I've just recently got into messing with tubes and it can really change the overall character of an amplifier.

 

[ThunderMonkey]

*Preamp tubes have dual triodes...that means it has (2) sides with current running through it.
V1 preamp is responsible for and delivers your gain/distortion....yep, right at the input stage, first in line after your guitar cable engages the input jack.
This V1 preamp stage in a Mesa only uses one side to create your gain color (and it gets hammered) so a good strong tube is absolutely necessary for good tone as this is where it starts.
All the rest of your preamp tubes V2,V3 use both sides of the triode as well as V4 (efx loop) and V5 (phase inverter).
Most people believe V5 has to be * "balanced" (i think so too) because this is the stage that hits your power tubes with current from all the stages of your preamp. So you could say V2/V3 control your EQ highs/mids/lows.

* meaning both sides of the triode are equal in the way they pull positive and negative current to the plate (where all the electrons are moshing)

Different preamp tubes (and power tubes) are made with variables....metals, plate designs, vacuum variances and glass....all these characteristics are going to affect and color your tone, sometimes in a bad way (though someone else may love it) or a good way, the tone you like to hear that sounds full and alive.

Of course, this is all subjective 8)