Praise for my first gen PRS Archon after blowing a power tube

[Ascension]

Had a power tube short during an event in my First gen PRS Archon. The amp never quit and only noticed slight drop in volume and headroom. Didn't even blow a fuse! Took out one of the screen resistors on the tube socket, but finished the event without incident and still sounded good. That was impressive!!! Had my tec take a look because the amp ran after the tube failed, just to make sure that it didn't get more than the screen resistor. Built like a TANK and a very impressive performance here!
Got her back on Thursday and threw this together over a Smooth Jazz jam track. Have missed the smooth sustain and dynamic response of this amp a lot. This is my favorite amp of all time, and I wish they still built these instead of SE version import amps they now offer as the Archon series! These amps are truly something special, as is my US built Custom 50 head also.
Clip running only my Boss DD 7 Delay and Ceetus verb on the cloudy setting with my 1993 Carvin solid KOA DC 127 hardtail with an Alt 8 bridge and Sentient neck.

 

[playas]

Glad it held up through the gig and that you have it back to fully working condition again.

 

[jeremy]

yeah, thats a testament to the design for sure

 

[Ascension]

yeah, thats a testament to the design for sure

I was shocked when I found the dead power tube after the event. There was only a little loss in volume and punch during the event, but nothing dramatic, I doubt anyone noticed anything happened but me. I never dreamed it was suddenly running at 25 watts on the single tube. That was impressive, to say the least! Dropped a new set of Ruby's in her, replaced a single screen resister, and the amp was fine.

 

[JMP/HBE]

"Blowing" a power tube is usually a sign of a larger problem.

 

[Ascension]

"Blowing" a power tube is usually a sign of a larger problem.

Not when the tube itself shorts.

 

[Solarflares]

"Blowing" a power tube is usually a sign of a larger problem.

That’s why I use 50’s and 60’s Mullard, and GE valves that test above spec - headroom for days.
The tolerances of modern valves are pitiful in comparison.
They often can’t handle the basic plate voltage they are subjected to.
Add to that the cathode-bias resistor laziness of amp-makers, and these cunts are 0.1mA away from disaster most of the time.

 

[jeremy]

is cathode biasing laziness? i have a 5e7 tweed bandmaster type circuit with switchable bias, fixed to cathode. and i prefer the sound and feel of cathode most of the time

 

[JMP/HBE]

That’s why I use 50’s and 60’s Mullard, and GE valves that test above spec - headroom for days.
The tolerances of modern valves are pitiful in comparison.
They often can’t handle the basic plate voltage they are subjected to.
Add to that the cathode-bias resistor laziness of amp-makers, and these cunts are 0.1mA away from disaster most of the time.

 

[Binnerscot]

@Ascension Cool story, I like hearing gear go above and beyond expectations. I had a 10mm Glock with an aftermarket guide rod and spring.... it ate it and kept going without me ever noticing until I cleaned it and poured the shattered parts out. Reputations are earned from these stories.

 

[Solarflares]

I notice the Pearl Chorus pedal there.
Is that the early one with the Ratio control?
I used one for a while when I was broke in Wales.
Excellent pedal.

 

[Solarflares]

is cathode biasing laziness? i have a 5e7 tweed bandmaster type circuit with switchable bias, fixed to cathode. and i prefer the sound and feel of cathode most of the time

I did say Cathode-bias resistor laziness.
Stating in the manual that users can change valves without biasing - when in fact most valves are running way over 100% in their amp, and the resistors values should really be optimised by a tech with a scope and good ears.
This will of course vary from valve to valve, so it is entirely incorrect to assume cathode-bias requires no attention.

I tried cathode-bias for 2 months with a new amp from a pawn shop, before the valves red-plated. Bought Svetlana’s and had a good tech design an adjustable bias circuit. I so much preferred the amp this way. More controlled, less raucous. I expect the valves to last many years, as opposed to the 6 months that cathode-bias would allow for in a gigging amp.

But you know all that I’m sure.
If you like the sound and feel, then rock on.
Just don’t put any 60’s Mullards in there, or I’ll have to come round and sort you out.

 

[jeremy]

thats fair and i always check bias when swapping tubes, and will switch a resistor if warranted. for small amps, 5f2a and 5e3 for example, i havent had much of an issue. the mentioned 5e7 and some other amps, ive adjusted the value, but rarely.

 

[Securb]

"Blowing" a power tube is usually a sign of a larger problem.

Happened to me a lot in the 80s with my Fender Quad. However, that amp was on more than it was off, was gigged with and play on incrediblly hard.

 

[JMP/HBE]

I notice the Pearl Chorus pedal there.
Is that the early one with the Ratio control?
I used one for a while when I was broke in Wales.
Excellent pedal.

yep 1981 still going. Super brite, low noise.