[Smolder]

Two question...

If your doing a tap to a separate power amp from a twin, does pulling the tubes take care of the lack f load on the output transformer? Also, doesn't that raise the voltage to the rest of he circuit?

Second - is the use of head units to a 2x12 cab for tone or for looks? Why not leave he JBL 12's in the twin cab?

Thanks in advance.

[hippieguy1954]

Two question...

If your doing a tap to a separate power amp from a twin, does pulling the tubes take care of the lack f load on the output transformer? Also, doesn't that raise the voltage to the rest of he circuit?

Second - is the use of head units to a 2x12 cab for tone or for looks? Why not leave he JBL 12's in the twin cab?

Thanks in advance.

Everything you need to know about the amp mods is here: http://www.wald-electronics.com Scroll down to the bottom of the page and click on "pre amp mods".

Second - A head and a seperate cab is lighter because you can carry them seperately. Have you lifted a twin with 2 E120"s? It ways a ton! Each E120 is 50lbs! Also, there has always been the question of the speakers ratteling the pre amp tubes too much.

[Smolder]

Thanks man. I've read that info several times. The closest it come is:

"a.) regular preamp tap on one or both channels - a mono plug will short the ring to ground of the 14b jack. if either preamp tap is used with a mono plug the power section is rendered dead. "

I'm actually pretty content with the twin at half power with one D120. I have E's but put them in some floor monitors as I really prefer the alnico speakers. I planned to pull he chassis for another mod and thought I'd do the simpler pre tap in the event that I came across a Mac deal I could not pass up.

[hippieguy1954]

Thanks man. I've read that info several times. The closest it come is:

"a.) regular preamp tap on one or both channels - a mono plug will short the ring to ground of the 14b jack. if either preamp tap is used with a mono plug the power section is rendered dead. "

I'm actually pretty content with the twin at half power with one D120. I have E's but put them in some floor monitors as I really prefer the alnico speakers. I planned to pull he chassis for another mod and thought I'd do the simpler pre tap in the event that I came across a Mac deal I could not pass up.

It sounds like you know what your doin and know what ya want. The only thing, if I remember correctly, is that there might be a little more to it than just removing the tubes, but I can't remember where I was reading it. Might have been here somewhere or TGP maybe.
Someone will chime in.

[Smolder]

Second - is the use of head units to a 2x12 cab for tone or for looks? Why not leave he JBL 12's in the twin cab?
.

Answering my own question (odd I know). I recently obtained an incredible orange d120, all original cone. Sounded unbelievable in an avatar vintage 2x12 solo. Sounded great, but not as rich or deep in the twin cab.

[SarnoMusicSolutions]

I recall Healy telling the story about how in the late 60's they'd totally re-tube Jerry's Twins and he loved the sound, but then just 2 gigs later that tone was gone and he'd complain. So they figured out real fast that tubes IN a combo amp get beat to hell by the vibrations of the speakers being so close and in the same cabinet. That vibration just destroys that refined, detailed fidelity of fresh tubes. So they moved on to where half the Twins were amps only and the other half were simply cabinets. According to him, it may look like a lot of tie-died Twins in photos, but only half of them were actually powering the other half.

Keeping tubes out of combo amps greatly extends their life and their tone.


Brad

[Smolder]

Thanks Brad... Pretty much prefer heads and cabs, but have grabbed a couple combos lately. Surely I'm not as 'road' as all that, but point taken.

[hogan]

Second - A head and a seperate cab is lighter because you can carry them seperately. Have you lifted a twin with 2 E120"s? It ways a ton! Each E120 is 50lbs!

For the record, E-120's don't weigh 50lbs. They are about 20lbs. Still heavy none-the -less.

[TRG]

I recall Healy telling the story about how in the late 60's they'd totally re-tube Jerry's Twins and he loved the sound, but then just 2 gigs later that tone was gone and he'd complain. So they figured out real fast that tubes IN a combo amp get beat to hell by the vibrations of the speakers being so close and in the same cabinet. That vibration just destroys that refined, detailed fidelity of fresh tubes. So they moved on to where half the Twins were amps only and the other half were simply cabinets. According to him, it may look like a lot of tie-died Twins in photos, but only half of them were actually powering the other half.

Keeping tubes out of combo amps greatly extends their life and their tone.


Brad

That's one of the main reasons why I switched from my Fender Twin combo to the rack mount route. Just got so frustrated over the years with the tube rattle and weird harmonics/tone loss I experienced. I tried a couple differnt tricks including titanium tube rings and nothing would ever work.

[hippieguy1954]

Your right hogan 20lbs each..my mistake!