not matched set of tubes (noob question)

[mat]

this one looks cool:

http://www.dreamstime.com/royalty-free- ... mage256439

[Phil_S]

When you change Rk from 60 to 50, expect the plate voltage to go down. To each, his own, but I hardly see the point. 40mA @ 302V = 12.1W or 97% of max. Max = 12.5W. It is possible you will never get there.

[pdf64]

Pete are you saying that running continuous plate dissipation of 150-200% in most cases wont result in redplating?

My experience is that continuous plate dissipation needs to be up at those levels before redplating becomes noticeable.
The environmental light level may affect this to a degree, eg it's more obvious in a dark room.
Some EH 6L6 in a Fender I checked last night had a cathode current around 100mA, so well over 150%, without redplating.
Pete

[martin manning]

Thanks Pete. I've just never gone looking for this threshold before. I suspect that it varies from one tube design to another.

[mat]

double

[mat]

When you change Rk from 60 to 50, expect the plate voltage to go down. To each, his own, but I hardly see the point. 40mA @ 302V = 12.1W or 97% of max. Max = 12.5W. It is possible you will never get there.

I left the 60R in there. The clean channel is beautiful and actually quite fendery. OD channel has nice crunch. With a DIY BSIAB1-pedal it sounds quite dumbly to my ears. Germanium FF works wonderfully also. I'll try to record something on this week.

I like the rough look. Pic: https://www.flickr.com/photos/fuzzface1966/13865459685/

..the handle is from old belt..

[pdf64]

Regarding the 'threshold of redplating', my thoughts on this are that when a very thin, fine tolerance sheet metal assembly becomes red hot, unless it is specifically designed to accommodate the stress, there's a likelihood that due to the expansion forces it may become permanently physically distorted.
For a tube's plate that would probably affect it's key characteristics.
So the tube designer may be expected to factor in plenty of margin between the limiting plate dissipation and the onset of redplating, to ensure that the tube would be robust in service.
As a caveat on the above, I've only a general awareness of materials science!
I suppose there will be guidelines on this somewhere.
Pete

[mat]

Finally got time to record the amp. 6+ minutes mindless noodling, sorry for that https://soundcloud.com/mattit-1/vc30b

[NickC]

Finally got time to record the amp. 6+ minutes mindless noodling, sorry for that https://soundcloud.com/mattit-1/vc30b

Nice!

Sounds great ..... both tone and playing. Two thumbs up.

[mat]

Finally got time to record the amp. 6+ minutes mindless noodling, sorry for that https://soundcloud.com/mattit-1/vc30b

Nice!

Sounds great ..... both tone and playing. Two thumbs up.

Thanks NickC. I used one SM57 on grille and one borrowed AKG about one meter away of the speaker. Would be nice to know how to set the mics for a best results.

[cxx]

I had a couple of these. Great sounding amps. Nice clean channel that produces great Fendery overdrive tones at higher volumes. It lets more low end through to the power section than a Fender though. You can get some great spanky funk tones on the clean channel. The overdrive channel worked best for me at relatively low settings on the gain knob but higher overall volumes. I think getting the power section involved was key. A lot of good tones for very little cash.

I found that they went through tubes pretty quickly, power tubes especially. I liked the sound of the JJs which seemed physically robust. I think running them hot and the fact that they are mounted horizontally puts a lot of stress on them, that and being right next to the speaker.

I really like the speaker that came with that amp. Can't really find a new equivalent. I also like the tonespotter in this amp, but that is also discontinued. As a cautionary note, you can pop the stock speaker quite easily at volume. The preamp tubes also take a beating. One thing you might want to try is a low gain tube in v1. I had a 12au7 that in v1 produced the driest most clear tone, almost painful but interesting.

I kept mine alive as long as I could but they became platforms for new amps. Very nice for this purpose as the transformers and hardware are good and the chassis is large.

[mat]

I had a couple of these. Great sounding amps. Nice clean channel that produces great Fendery overdrive tones at higher volumes. It lets more low end through to the power section than a Fender though. You can get some great spanky funk tones on the clean channel.

I also like the Fenderines of the clean channel.

The overdrive channel worked best for me at relatively low settings on the gain knob but higher overall volumes. I think getting the power section involved was key. A lot of good tones for very little cash.

I'll try lower gain tube for the OD. OD channel from 1'38 on the clip + BSIAB1 DIY-pedal from 2'25.. Guitar was ES-339.

I found that they went through tubes pretty quickly, power tubes especially. I liked the sound of the JJs which seemed physically robust. I think running them hot and the fact that they are mounted horizontally puts a lot of stress on them, that and being right next to the speaker.

Horizontally ?

One thing you might want to try is a low gain tube in v1. I had a 12au7 that in v1 produced the driest most clear tone, almost painful but interesting.

I dont like clean-clean tones. I always seek for some dirt from the clean channel also

I kept mine alive as long as I could but they became platforms for new amps. Very nice for this purpose as the transformers and hardware are good and the chassis is large.

That is right. Now this seems to be a keeper. But you never know..

[cxx]

At least in the combo, the chassis is mounted knobs up and the tubes stick out parallel to the ground towards the speaker.

[mat]

At least in the combo, the chassis is mounted knobs up and the tubes stick out parallel to the ground towards the speaker.

Ok, never seen that before.

[M Fowler]

Some PRS amps are knobs up and tubes down.