Can I use KT88's in my MOD50 ?

[Franne500]

Hi All

Just bought a used MOD50 from a friend of mine - theese amps are IMPOSSIBLE to get here in Denmark - I am VERY happy with it, but i think it needs new tubes - I can't get a clean sound out of it - Slot 1 is a SL2 module and Slot 2 is EG3/4. I use channel one on the SL module for cleans.
It sounds like it is the power amp tubes that needs replacing - the sound is "dead" and bass is "flat" and I get a break up that is not very musicla but it seems to compress and flatten my sound when I hit the strings hard.

I LOVE the sound of EL34s - and could replace the current tubes with GTE34LS but I could also experiment and try the KT88's - Has anyone in here any experience with this ?

 

[JKD]

The SL2 and EG3/4 are quite high gain but you should be able to get a clean ' ish sound out of Ch1 from each, with the gain at 9 o'clock or lower.

Did you check the bias on the power tubes? It can drift, especially in transit and as tubes age.

Preamp tubes fade over time and there are three in the head (input buffer closest to input, fx loop driver and the PI closest to power tubes.)

Might be worth making sure the input jack and fx loops jacks are clean - since they can interrupt the signal path. (I use contact cleaner on a regular 1/4 plug and work in/out.)

It can take KT-88s, I set mine at 42mA, though I think they can go higher.

Excellent amp, when you get it dialed in you will love it!

 

[Franne500]

Great info - Thanks !

I will definately check the bias before ordering new tubes. I have a bunch of 12ax7's lying around, so when I get the time I will experiment with them.
How is the sound of KT88 vs EL34?

 

[JKD]

Great info - Thanks !

I will definately check the bias before ordering new tubes. I have a bunch of 12ax7's lying around, so when I get the time I will experiment with them.
How is the sound of KT88 vs EL34?

The KT-88 is a very 'wide' sounding tube, it provides amplification across the spectrum.

What I hear is more lows, crisp highs and a bit more mid balance. I love KT-88s for heavy tones.

Someone commented that if you like EL34s and use KT-88s that you can up the mids a little more on the module.

 

[Franne500]

Cool ! I think I will give them a try - I am definately relying very much on mids ..... I already run them at 2 o'clock