EL34s in ProMod

[shik]

Long story short, I had to do a full retube plus an extra pair on my promod and KT88s are expensive and no one ever stocks them. This got me thinking about modding the promod to EL34s. I love the PM, but tend to prefer EL34 tubes more than KT88s and KT88s are more expensive than I want to pay for every time I need to re-tube.

I have read of some people do it and was curious if anyone had any experience. What would I need, how do I do it, and is it worth it?

Any help would be greatly appreciated.

[sasquatch]

I would recommend talking to Scott. I'm pretty sure it requires either a resistor mod, or a different resistor all together. I've seen a few "how to" posts with pics on switching from EL34 to KT88, and they had to install a different resistor. Didn't look too difficult.

[shik]

Thats kind of what I was figuring. Would it sound pretty similar to the quickrod?

[sasquatch]

After the resistor mod (or substitution) and a new set of EL34's (try the Sino's) you'll basically have yourself a Quick Rod.

[benhur]

from what i've been told it's a different resistor on the bias pot and you're good to go. from my experience (i have a pro mod with Mullard el34's in it currently), the amp sounds killer. there is actually a clip of mine in the clips section of the forum. i bought it this way used. personally i was concerned that the QR wouldn't have the balls i want for modern rock stuff, and i would need the kt88's for that modern sound. baloney. this thing flat out kills from light to heavy. there is a guy on here "Paulyog" who knows what he's doing, or just call the shop and ask Scott!

[splawndude]

What Sasquatch said is correct. I would double check with Scott too. I may be wrong about this but I thought the resister mod was only when going up to KT88s - not going to EL34s. You will definitely want to bias it. There is a thread either way with more specifics on the resistor change. If you need help finding it, let us know. I want to say it was FastRedPonyCars thread.

[shik]

If you guys could link that to me, it would be great!

[philm]

Apr 21, 2011 19:47:18 GMT -5 splawndude said:

... I may be wrong about this but I thought the resister mod was only when going up to KT88s - not going to EL34s. ...

Has anyone verified this? Could the Pro Mod take EL34s with just a rebias but no resistor modification?

No, I haven't called Splawn myself yet, just curious.

[rocknrolla]

I was thinking the same thing for my Nitro. The KT88's are crushing but they cost twice as much as EL34's. I'd like to wire both resistor values in parallel and select either with a switch. That way I can run either tube.

[angusdeadking]

I had my Pro-Mod (33rd Splawn built I believe) changed over to EL34B's by Josh and it really brought it a new life. I was never happy with the KT88's, too loud and hard to tame in most live situations and especially at home. I was also looking for a bit more raw aggression. The EL34B's are really close to the KT88's in size and construction and after the conversion, I really felt inspired again by the new range of sounds that were opened up to me.

[rocknrolla]

I did the EL34 swap in my Nitro. The KT88's it came with were bad so I borrowed a pair from my buddy. The KT's were a little to modern sounding (scooped) for me and the EL34's just give it such a rich midrange. I don't think any low end went away because I still rattle stuff off the shelves. It just has to compete with the added mids.

[DonaldDemon]

I had to change the resistor last time I retubed because the KT88’s I bought were rated too low and I couldn’t get them biased down enough. I’ll have to search for the thread but instead of piggy-backing a resistor you are changing it out for a lower value, I believe. Either way you do have to swap resistors. Not that bad, I didn't even desolder mine, just cut it off and soldered to the remaining legs.

I may try to get a high rated pair of EL34s in there next time because the KT88s are getting costly.