What I have seen is AI just searches forum posts and regurgitates what it finds random people saying, without any research into the qualifications of the poster. And clearly it can't listen to the results or even test them.
And then is says authoritative nonsense like this "The best compromise is 330Ω – 360Ω for the cathode resistor with 55 – 60mA bias current for a natural, realistic, and immersive soundstage." I tested this and it adds several % of THD and reduces the power output substantially.
Hi there,
My name is Ray, from Scotland and I'm very late to the A10/12 party...
I come from being a self taught, early solid state, Sansui restorer but I've been hankering for SET tube amp for a while.
I'm doing an A10 and my B+ is around 360v, is that reasonable number to proceed with the mods?
It was fitted with JJ-Tesla E34L Outputs,
A GZ34 rectifier and 6N2P Voshod Rockets by the previous owner but it is standard apart from these tubes...
(Photos attached, measuring in the correct place?)
I've also erred on the side of safety, by fitting that bleed resistor before anything else, to get that quick power down....
My name is Ray, from Scotland and I'm very late to the A10/12 party...
I come from being a self taught, early solid state, Sansui restorer but I've been hankering for SET tube amp for a while.
I'm doing an A10 and my B+ is around 360v, is that reasonable number to proceed with the mods?
It was fitted with JJ-Tesla E34L Outputs,
A GZ34 rectifier and 6N2P Voshod Rockets by the previous owner but it is standard apart from these tubes...
(Photos attached, measuring in the correct place?)
I've also erred on the side of safety, by fitting that bleed resistor before anything else, to get that quick power down....
Attachments
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So, after scraping the internet with AI, for a couple of days, the responses I'm seeing are showing that a B+ of 360v is too high for these mods?...
Any advice would be much appreciated
@StepheK
Going to try the original rectifier tube, to see if that lowers the b+...
I'm a complete novice to tubes but, I learn fast... and don't need telling twice
Any advice would be much appreciated
@StepheK
Going to try the original rectifier tube, to see if that lowers the b+...
I'm a complete novice to tubes but, I learn fast... and don't need telling twice
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I've been listening to my STOCK Reisong A10 extensively which came with all tubes upgraded and I'm writing this as a record/description of the unmodded amps signature sound.
I'm finding the amp very mids centric, with bass and treble rolled off considerably, like the music is almost 'spherical' or in a bubble.
The only dynamism is in the mids, with the bass & treble very flat and dead sounding.
There is good left, right seperation but, there isn't much holographic'ness going on.
It's quite pleasant to listen to, the midrange smoothness and clarity is gorgeous but at the same time the performance seems small and closed in.
Surprisingly, there is good depth.
I'm playing it through 88db 1975 Wharfedale Denton 2XPs which is a poor partner but, it's all I have just now.
It's up against a 1968 Sansui AU222, an amp with a legendary reputation of sounding very tube like and I can confirm it is much more holographic than this amp but at the same time, I can hear the difference of class AB.
I'm finding the amp very mids centric, with bass and treble rolled off considerably, like the music is almost 'spherical' or in a bubble.
The only dynamism is in the mids, with the bass & treble very flat and dead sounding.
There is good left, right seperation but, there isn't much holographic'ness going on.
It's quite pleasant to listen to, the midrange smoothness and clarity is gorgeous but at the same time the performance seems small and closed in.
Surprisingly, there is good depth.
I'm playing it through 88db 1975 Wharfedale Denton 2XPs which is a poor partner but, it's all I have just now.
It's up against a 1968 Sansui AU222, an amp with a legendary reputation of sounding very tube like and I can confirm it is much more holographic than this amp but at the same time, I can hear the difference of class AB.
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I'm getting @ EL34
25v at Cathode
337/338v at the plate...
In Scotland, our AC at the plug is 240v
Attachments
The outlet plug voltage is irrelevant and only impacts the transformer primary wiring. After the mods it will likely be spot on with the voltages I show on the schematic.
Thanks for your help
I'll let you know how I get on
Only vague concern I'd have is the heater voltage. If its 6.3 vac +/- 0.3 volts, the transformer is wound for the right line voltage. Not uncommon on the US-spec stuff at least to find the heater supply running on the high side, which means the primary is meant for lower voltage than we actually get.
arts
Addicted Member
And before ai there was "but the internet says..."
Outside of the forums I'm not a very "filtered" guy, so my reply to either of those statements is usually "Then why the f**k are you wasting my time?"
yeah, have dealt with this in the car world too. Equally dumb is the "It can't be that because thats expensive / difficult / inconvenient / etc".
What values should I be seeing?
arts
Addicted Member
Oh man, my best story of ignored advice was a guy I played in a band with. He was rebuilding his BSA.
Calls me up and asks me if you have to check check the piston ring end-gaps when using new pistons in a freshly machined bore. Of course, I replied, you always check. Better safe than sorry. Then he starts going on that the shop that did the machining and sold him the pistons said "Don't worry about it, we've never had a problem".
And besides, he'd already installed them and the barrel was on the bike with a new base gasket with gasket goop blah blah blah...again, another case of "then why the f**k are you bothering me?"
Poetic Justice: He didn't listen and it seized up on his first ride. All for the price of an hours work and a three buck gasket.