SOLD Matched pair GZ34 valves or equivalent

[m7rso]

Anyone got a nice strong matched pair, no JJ’s though please I have a pair already. Please dm with posted price to not-so-sunny Liverpool.

 

[audio_PHIL_e]

Please forgive my ignorance, but what kind of circuit would require a matched pair of GZ34s?

 

[m7rso]

Pair of monoblock amps, one valve has given up the ghost after only maybe 200 hours of use, pita. So replacing both, one from each block.

 

[m7rso]

Please forgive my ignorance, but what kind of circuit would require a matched pair of GZ34s?

As above

 

[audio_PHIL_e]

Pair of monoblock amps, one valve has given up the ghost after only maybe 200 hours of use, pita. So replacing both, one from each block.

I've heard of matching output valves but not rectifiers. I'd have thought you could get away with just replacing the one that failed. Much cheaper.

 

[audio_PHIL_e]

GZ34s sometimes have a reputation for being a bit, er, fragile. I'm not surprised you had one that failed. I take it you knew it was the GZ34 by swopping from the other monoblock?

 

[Mikeb]

Surely if the amps are monoblocs as you stated there is no need for matched GZ34 rectifiers as both amps are totally separate. Matching is only usually necessary when the valves are on the same circuit of say an integrated amp or push pull output stage.

 

[audio_PHIL_e]

IMO there isn't much point in trying to "match" rectifiers as they either work or they don't. I could imagine wanting to match o/p valves both within a monoblock and between monoblocks, in order to ensure not only a clean signal but also channel balance.

 

[m7rso]

IMO there isn't much point in trying to "match" rectifiers as they either work or they don't. I could imagine wanting to match o/p valves both within a monoblock and between monoblocks, in order to ensure not only a clean signal but also channel balance.

Although I have had valve amps for quite some time, I am a valve noob but i will take your advice and try one of the few I have here. In asking for matching valves, I was trying to give the amps the best chance of sounding the same, with equal output etc. the annoying thing is the the rectifiers I had in previously gave me no trouble whatsoever, but this one has kicked the bucket after not much use at all. All of the valves were replaced last year when I had the amps serviced. onward and upward….

 

[m7rso]

GZ34s sometimes have a reputation for being a bit, er, fragile. I'm not surprised you had one that failed. I take it you knew it was the GZ34 by swopping from the other monoblock?

The valve thats gone down started to brighten and ‘fizz‘ for want of a better word. Immediately removed it and tried the opposing valve in its place to ensure it was the valve and not some other problem. Thanks for the advice.

 

[audio_PHIL_e]

The valve thats gone down started to brighten and ‘fizz‘ for want of a better word. Immediately removed it and tried the opposing valve in its place to ensure it was the valve and not some other problem. Thanks for the advice.

Hmmm ... that could be a dud valve, but it may be worth checking that its heater was not being supplied by too high a voltage. Sometime amplifiers are "configurable" for their mains supply voltage - you may find the one that is always failing has the mains on the 230V tap, while the one that seems reliable is on the 240V tap. If so, try moving it to the 240V tap. HTH

 

[audio_PHIL_e]

The valve thats gone down started to brighten and ‘fizz‘ for want of a better word. Immediately removed it and tried the opposing valve in its place to ensure it was the valve and not some other problem. Thanks for the advice.

Hmmm ... that could be a dud valve, but it may be worth checking that its heater was not being supplied by too high a voltage. Sometime amplifiers are "configurable" for their mains supply voltage - you may find the one that is always failing has the mains on the 230V tap, while the one that seems reliable is on the 240V tap. If so, try moving it to the 240V tap. HTH

 

[m7rso]

Hmmm ... that could be a dud valve, but it may be worth checking that its heater was not being supplied by too high a voltage. Sometime amplifiers are "configurable" for their mains supply voltage - you may find the one that is always failing has the mains on the 230V tap, while the one that seems reliable is on the 240V tap. If so, try moving it to the 240V tap. HTH

Roger that Phil, cannot hear any discernable difference with the original rectifier replacing the dud. Ive had these amps 10 years and this is the first time i have lost a valve but I will keep an eye on it just to be on the safe side. If they are voltage configureable, it will be on the inside. Many thanks again. They are Matamps btw based on the mullard 5-20.

 

[m7rso]

Thanks

IMO there isn't much point in trying to "match" rectifiers as they either work or they don't. I could imagine wanting to match o/p valves both within a monoblock and between monoblocks, in order to ensure not only a clean signal but also channel balance.

thanks phil, saved me a few quid