I got a pair of the 300B-Z, everybody is talking about and initially it sounded bad. After I cook them for 50 hours its now more balanced with clear mid and highs but the bottom end is just not there, also there is lack of sound stage. I make A B comparisons with a generic 2A3. on the same amp same driver tubes and same source, just rolling tubes.the 2A3 is great on the low frequencies just not as good in mids but it has a great sound stage. m'I missing something? did I got bad tubes? or I just need to cook them more? Any 300B-Z owners please advise.
Thanks
Michael.
Thanks
Michael.
Perhaps I am missing something here. A 300B's filament is 5 volts while a 2A3's is 2½ volts. Did you take this into account? Please be more specific about this. 😕
I have never heard or known of an amplifier that "automatically" changes filament voltages. Unless you have to throw a switch which is manually doing it. Care to say what the amplifier is?
It has a microchip that detects current draw depending the tube and activates relays to change voltages. Pretty cool! Elekit TU-8233
ELEKIT speaker
Do you have a 300b-Z? does it need 300 hours to open up?
Ok, live and learn. Thanks. No, I have no 300B's except original WE's and they are currently resting comfortably in the attic waiting for work.
Michael,
The Hi$$End brands, the audio mags and the Power that Be in audio dont want people knows that any cheap EL34 wired in Triode will delivery great sound quality, with a holographic soundstage better than most 300B.
Save you have deep pockets the 300B is the wrong tube to invest due high price and doubtful return on quality, unless you can afford EML, Takatsukis etc
My 2 cents
The Hi$$End brands, the audio mags and the Power that Be in audio dont want people knows that any cheap EL34 wired in Triode will delivery great sound quality, with a holographic soundstage better than most 300B.
Save you have deep pockets the 300B is the wrong tube to invest due high price and doubtful return on quality, unless you can afford EML, Takatsukis etc
My 2 cents
If you want to include sound quality vs price as a criteria, then you can't ignore the JJ 2A3-40 as a top performer. I also have the AVVT solid plate and mesh plate but use the JJ most of the time.
I know this may be hard to believe, but some people "like" the sound of 300b's.😉
jeff
So far this 300B-Z has no bottom end nether big sound stage! I do have great mid range thought, do I have bad tubes?
I do have the normal cheap Shuguang 300b and they are superb. Very solid base and good soundstage. I did have several other 300b over the years, but will stay with Shuguang as I cannot afford WE.
That's incredible, it could uses current regulators with detector of load. That's and incredible solution for a problem that doesn't exist.
"So far this 300B-Z has no bottom end nether big sound stage!"
Does this amplifier automatically re-bias the tubes for optimum idle current?
Maybe some measurements are in order. Cathode current and filament voltage.
Does this amplifier automatically re-bias the tubes for optimum idle current?
Maybe some measurements are in order. Cathode current and filament voltage.
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Dear Musikofilus, Did you take some measures from the filaments, bias and power? What part of the load curve is working.
Maybe whatever 300B in this place will give the same.
The output transformer, is for 300B and for 2A3? or worst: is for 2A3 and 300B?
Maybe whatever 300B in this place will give the same.
The output transformer, is for 300B and for 2A3? or worst: is for 2A3 and 300B?
I think the problem here is twofold. First, in today's world of tubes, what were once specifications and manufacturing tolerances are now, at best, only rough ballpark guidelines. For this reason alone picking tubes has become a crap shoot.
Secondly, I'm of the opinion that your amp may be manufactured to a price point, and given the ability to interchange output tubes is more for sales then sound fidelity. In any design comprises have to be made and this may be one result. 300Bs and 2A3s have some similarities, but more differences. I'm with "smoking-amp" and "dady" in that measurements are necessary.
Secondly, I'm of the opinion that your amp may be manufactured to a price point, and given the ability to interchange output tubes is more for sales then sound fidelity. In any design comprises have to be made and this may be one result. 300Bs and 2A3s have some similarities, but more differences. I'm with "smoking-amp" and "dady" in that measurements are necessary.
They sounded good from the beginning, but even better after about 50 hours.
I think they are a real bargain.
for the 2A3 was 2.5v, 36v, 250v for the 300b should be 5v, 48v and 300v but I haven't verify that I will check and report back.
True too! I just couldn't decide witch way I wanted to go at the time, maybe the bottlehead amp option was a better one!
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