traynor ygm3 high plate voltage

[mikhett]

I just picked up a 73 traynor ygm 3.It has fixed bias an has 2 el84 optput tubes.I measure -18.5volts on the grids and 410 on the plates.It sounds fine when played but i dont like the high p[late voltage although there no sign off red plating.Any ideas how i can get the plate voltage down?

[imaradiostar]

Not worth changing. They work fine as is, why mess with it? There are a number of modern tubes that can take that voltage with no trouble. If you're worried about reliability you can always increase the value of the screen resistors.

Or you could always sell it and get an amp with lower plate voltage.

jamie

[Chuck H]

+1
This is a popular model for all the things that are good about it. Loud (for a pair of el84's) and dynamic. Very crunchy when overdriven. Tubes last just fine when the amp is run clean, which is very possible with a good high efficiency speaker. Then use a pedal for distortion. Crank it full time and the tubes wear out much faster. A few months before performance slides off or the tubes get noisy.

Lowering plate voltage will increase tube life some, but at the expense of volume and dynamics. You'd need to get down to about 340Vp before the el84's start to give that classic "chime". At that point the preamp may not be suited for the power amp as far as tone. Don't know, I've never tried it. My point is that el84's can be like two very different tubes. At higher voltages they perform very strident and can surprise you with their bass response and volume. Some tube life is sacrificed at high voltage if the amp is run loud all the time. At lower voltages they become more "creamy" and "chimey" but lose dynamics and volume.

If you really want to lower the voltage, I'd say use a 10V or 15V Zener to get close to 400Vp. This seems to be a magic number for many el84 amps with a high Vp. But I honestly havent heard any complaints from other owners if this amp model, some of which have 428Vp. Everyone seems to like these amps. If you don't, sell it and get an amp you do like.