Hello tube amp experts,
I'm a new bee in the world of tube amp.
Lately I've got the Cobra Audio tube amp, whicht is based on the 4*PSvane EL34/6CA7.
Unfortunately 2 of the 4 tubes are weak (34mA and 23mA) and the other 2 tubes are still strong (49mA and 50mA as specified by Psvane).
And I intend to replace the weak tubes with 2 Philips EL34 tubes (50mA and 51mA), which I bouht from a regional tube collector. Because he only had 2 Philips availble, I had no choice.
So I wonder if I can combine the Psvane with the Philips in my amp.
Maybe this is the logic thought but will it work out in term of technical an tonal.
I hope you can shed some light on this.
Thank you and my appreciaition for your advice.
I'm a new bee in the world of tube amp.
Lately I've got the Cobra Audio tube amp, whicht is based on the 4*PSvane EL34/6CA7.
Unfortunately 2 of the 4 tubes are weak (34mA and 23mA) and the other 2 tubes are still strong (49mA and 50mA as specified by Psvane).
And I intend to replace the weak tubes with 2 Philips EL34 tubes (50mA and 51mA), which I bouht from a regional tube collector. Because he only had 2 Philips availble, I had no choice.
So I wonder if I can combine the Psvane with the Philips in my amp.
Maybe this is the logic thought but will it work out in term of technical an tonal.
I hope you can shed some light on this.
Thank you and my appreciaition for your advice.
Use the two Philips in one channel and look around for a second set of Philips/Mullard/Valvo etc for the other channel in the meantime.
How did you come to the conclusion that tubes were weak ?
Do they sound bad ? Do they have trouble keeping right bias ?
On board there 2 * El34 tubes per channel.
I had on the Left the tubes 50mA and 34mA.
And on the Right channel the tubes 49mA and 23mA.
The right channel sounded weak.
Couple days ago I took the tubes off and had them measured.
So I know now which tubes are bad.
I also know that I have to replace 4 Psvanes tubes at once. But 2 tubes are still good as the measurings are about 50mA. So I wish to use them in combination with the 2 Philips tubes.
I had on the Left the tubes 50mA and 34mA.
And on the Right channel the tubes 49mA and 23mA.
The right channel sounded weak.
Couple days ago I took the tubes off and had them measured.
So I know now which tubes are bad.
I also know that I have to replace 4 Psvanes tubes at once. But 2 tubes are still good as the measurings are about 50mA. So I wish to use them in combination with the 2 Philips tubes.
PSVane (Horrible Name) are the latest iteration of GuiGuang/Shuguang (Cheapo Chinese) things and are not much cop--For some daft reason they are often extremely expensive, with daft versions and painted glass--but still not much cop.
Better to hunt round for some decent Mullard/Philips NOS tubes, may pay a fair bit--but at least they'll last.
IF you HAVE to buy new, could try JJ or Electro-Harmonix....
Better to hunt round for some decent Mullard/Philips NOS tubes, may pay a fair bit--but at least they'll last.
IF you HAVE to buy new, could try JJ or Electro-Harmonix....
One : ignore the "measurement". The best tubetester is your own amp. If they
work here - then keep working them.
Two: did one channel actually sound bad ? If so, install the 2 phillips here and go on listening. Don't base your tubechenges on a random tubetester.
Three: purchase a matched quad el34 from a reputable vendor and have as spares
Whenever your amp sounds suspicious , grab a spare tube and try them. If they
cure the problem - fine, throw away the old ones. If not , change back.
Four: sell the tubetester. It won't make you happy.
work here - then keep working them.
Two: did one channel actually sound bad ? If so, install the 2 phillips here and go on listening. Don't base your tubechenges on a random tubetester.
Three: purchase a matched quad el34 from a reputable vendor and have as spares
Whenever your amp sounds suspicious , grab a spare tube and try them. If they
cure the problem - fine, throw away the old ones. If not , change back.
Four: sell the tubetester. It won't make you happy.
The Siemens/RFT EL34 is an excellent sounding tube. I quite much prefer it to the Philips/Mullard EL34. Now, the Mullards aren't bad, but IMHO not worth the money they ask for them compared to JJ's EL34, which is also quite good.
Regarding the OP, I assume you're having a push-pull amp? I'm just too lazy to google, sorry... But anyhow, if it's a PP amp, don't use mixed pairs. Otherwise you risk having elevated distortion levels. A push-pull amp relies on having it's output tubes as close to identical as possible. You probably won't break anything even if you mix Philips and Psvane, but it's not going to give you optimal performance.
Regarding the OP, I assume you're having a push-pull amp? I'm just too lazy to google, sorry... But anyhow, if it's a PP amp, don't use mixed pairs. Otherwise you risk having elevated distortion levels. A push-pull amp relies on having it's output tubes as close to identical as possible. You probably won't break anything even if you mix Philips and Psvane, but it's not going to give you optimal performance.
I forgot to mention here. Actually I can get 4 Ultron EL34 from another tube collector somewhere in The Netherlands.
He told me that the Ultron tubes are Germany made (prob. by RFT) and they are as good as Siemens tubes.
What are your opions on this?
He told me that the Ultron tubes are Germany made (prob. by RFT) and they are as good as Siemens tubes.
What are your opions on this?
Maybe you should re-read my previous post. The RFT is an excellent tube, I've several pairs (though I'm not letting any of them go), and some XF2 Mullards, and I'd say at least in my amps the RFT's win hands down.
Of course, YMMV.
Of course, YMMV.
Going back to the original question: yes you can put different brands in each channel. It'll work but not be the best.
Different brands can perform differently in different scenarios. In my PP EL34 amp my 20 year old Chinese Valve Art EL34s put out as much power in pentode mode as various generations of Dutch or English Phillips/Mullard. In triode however, the Valve Arts put out about 10% less than the Phillips.
The quad of Ei EL34s (small beam tetrodes) put out less in pentode and a lot less in triode.
What I'm saying is: stick to one brand (and generation).
I have some Ultron labeled ones as well. They are east German RFT 'dimple tops'. I've used them in guitar amps in the past. Get them if the price is OK.
If they are much more expensive than current production ones (through a reputable dealer) it might be wiser to put that money elsewhere in your system.
Current production is OK (mixed opinions about JJ on this forum). Whether you can hear differences depends on your amp, setup and ears.
Different brands can perform differently in different scenarios. In my PP EL34 amp my 20 year old Chinese Valve Art EL34s put out as much power in pentode mode as various generations of Dutch or English Phillips/Mullard. In triode however, the Valve Arts put out about 10% less than the Phillips.
The quad of Ei EL34s (small beam tetrodes) put out less in pentode and a lot less in triode.
What I'm saying is: stick to one brand (and generation).
I have some Ultron labeled ones as well. They are east German RFT 'dimple tops'. I've used them in guitar amps in the past. Get them if the price is OK.
If they are much more expensive than current production ones (through a reputable dealer) it might be wiser to put that money elsewhere in your system.
Current production is OK (mixed opinions about JJ on this forum). Whether you can hear differences depends on your amp, setup and ears.
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