Increase signal to power output section ?

[jvk]

How could the level delivered to the ouput section be increased other than by putting a boosting device in the loop ? Circuit modification ?

It seems that by placing an equalizer in the loop the full power of the head (what I would expect from a 50W) becomes available whereas without it the overall volume accessible is drastically reduced and seemingly only increases saturation after noon on the master.

[Ayton(e)]

I can never quite believe the occasional player who says a Splawn isn't loud enough for him (have you got other toys in the loop that could be sucking volume?) but slaving is what most do when their favorite amp can't go loud enough.

[speedemon]

Hmm,

sounds like you either have the loop volume too low on the amp, or yes, something in the loop is sucking level. Others have had this problem, and they had remove items 1 at a time to find the culprit. If you just want to hit the power section harder, I would go with a good clean boost before effing with the amp (which given the lifetime warranty, I would avoid altogether).

Good luck!

[jvk]

Thanks for the responses, without anything in the loop there is a small difference. I love the amp, feel, sound etc., it just has less overall output than the 50W head (old Mesa DC-5) it replaced on the same cab.

With the EQ boost engaged in the loop the characteristic sound is exactly the same just much more sheer volume.

On a side note you could also create a clean channel by plugging the guitar into the EQ and then the loop return bypassing the preamp.

I replied to another's post regarding related info in the past:

splawnfans.proboards.com/index.cgi?board=competition&action=display&thread=7848

[gtguitarworks]

whats the wattage on your speakers? I just went from 25w greenbacks to 60w vintage 30s because it sounded like my competition was killing the GreenBacks due to the fact that I have a very loud drummer and this amp for a 50w amp is just as loud if not louder then my 50w 2204 which I always thought sounded more like a 70w in Marshall Wattage which seems a lot louder then the ratings on Fenders amps and other Co's. In fact my 2210 100w jcm 800 didn't seem that much louder then my 2204, Seemed like it was only about 25w louder then an actual 50w louder. That 2204 was extremely loud and that's why I only wanted a 50 Splawn. the 50w Splawn seem harder to find the 100w splawns - used. Anyways.. Point being, Try a louder speaker, I hear that the speaker Zakk Wylde's Plays though is like 200w speaker and metal players love them. sure would make for a heavy cab though, lol good luck.

[speedemon]

With your Splawn, you can get more perceived volume by dialing up the mids and treble. The Splawn speaker is pretty sensitive, but Eminence and some others make speakers at 100 + db sensitivity (typical celestion is 97 or 98 db), mo loudah! Most speaker makers publish this rating, so it is easy to compare.

don't know the specifics of amp design, OT performance, but I know that at 100w and 4 speakers I get stupid volume from my Splawn. 6L6 tubes do create some more "power" than a similar EL34. No doubt the Mesa and Fender offerings are designed to compete with a 747 landing, and our Splawn is not really.

Sounds like your eq has the problem licked.

Take it easy!

[jvk]

The speakers and cab are same as previous head used, Mesa C90 and Weber C1230-55 both 8ohm and fairly high efficiency. They sound great together and have no problem handing the power produced by the Compy or the previous head. Perhaps the DC-5 was underated.

I had tried some EMI Wizards for their high efficiency but was not happy with the tone (though markedly louder), even after many hrs of test tone pumping for break in.

The EQ in the loop is a quick easy answer but from a technical perspective what stages could be adjusted. Phase inverter feeding power tubes or last stage out from preamp to phase inverter.

Guess I really should measure the output power with a sig gen for 1KHz input level and dummy load on output to calculate the actual wattage.

[greglecompte]

how old are your tubes ?

[jvk]

Retubed and biased a few months ago. Just seems like there is so much more (seemingly) clean power available by applying a level boost in the loop. Could be useful to be incorporated to the circuit topology to begin with.

Another suggestion recently was to raise the value of the grid leak resistors in the power amp but will have to measure output power beforehand. This could allow more drive signal from the long tailed pair to reach the grids of the EL34's. Re-biasing the amp would be necessary.