I bought 2 sets (4 total tubes) of these to add some variety to my tube collection:
Ei 6BQ5 / EL84 – Upscale Audio
I have a Decware UFO2 and it is compatible with EL84s, and I have used other EL84 tubes in it, no issue, this amp begs for tube rolling.
The ones in the link arrived in the mail, popped them in, and the volume was MAYBE 5% what it should have been, and what was there was muffled and muddy (100% useless, there was just 'something' barely playing). Tried the other two, same thing. Long story short, either they are not compatible or they all happen to be defective.
Any idea? Why would they fit, properly heat up (heaters came on as expected), play 'something' but not work? No biasing in the amp...and they work fine with a range of EL84s.
They will be going back tomorrow, but now I have zero confidence in buying other EL84s because I have no idea what was happening.
Thanks!
Ei 6BQ5 / EL84 – Upscale Audio
I have a Decware UFO2 and it is compatible with EL84s, and I have used other EL84 tubes in it, no issue, this amp begs for tube rolling.
The ones in the link arrived in the mail, popped them in, and the volume was MAYBE 5% what it should have been, and what was there was muffled and muddy (100% useless, there was just 'something' barely playing). Tried the other two, same thing. Long story short, either they are not compatible or they all happen to be defective.
Any idea? Why would they fit, properly heat up (heaters came on as expected), play 'something' but not work? No biasing in the amp...and they work fine with a range of EL84s.
They will be going back tomorrow, but now I have zero confidence in buying other EL84s because I have no idea what was happening.
Thanks!
I would have a look at the voltages around the valves to see what is going on.
Might give a clue.
Might give a clue.
If the amp is still working with the originals better send those back & get replacements. Hope nothing in the amp is cooked.🙁
It's unlikely they are all defective, so that circuit must require a certain range of tube parameters
that those tubes just don't reach. You'd have check their electrical performance in-circuit.
For example, some current EL34 tubes by design have low emission and won't work in a fixed bias
audio amp, even though they will work in self-bias guitar amps.
that those tubes just don't reach. You'd have check their electrical performance in-circuit.
For example, some current EL34 tubes by design have low emission and won't work in a fixed bias
audio amp, even though they will work in self-bias guitar amps.
Yup, everything fine with the originals back in. I used it for maybe 30 seconds, just enough to let things warm up and hear something was very wrong.
FWIW, it seems this amp is pretty hard to hurt unless you were really trying to (like shorting between tube socket holes or something). Not saying that makes it good, bad, whatever, it just seems you can abuse the snot out of it and it won't care.
I will not be ordering replacements of these exact tubes. Either the amp hates the tubes, or even if I got 4 bad ones, not sure I want to try again on these (and Upscale probably doesn't want to deal with this again!)
FWIW, it seems this amp is pretty hard to hurt unless you were really trying to (like shorting between tube socket holes or something). Not saying that makes it good, bad, whatever, it just seems you can abuse the snot out of it and it won't care.
I will not be ordering replacements of these exact tubes. Either the amp hates the tubes, or even if I got 4 bad ones, not sure I want to try again on these (and Upscale probably doesn't want to deal with this again!)
Agree it would be odd they were all bad. What is confusing is I cannot find anything suggesting anyone else has had EL84 compatibility with this amp, either new production or NOS. I understand there are fickle, finicky amps, and this does not appear to be one of them.
Sounds like you are lucky to be able to send them back.
90-DAY WARRANTY Defective tubes will be replaced with like items only; carefully read the Warranty Policy
for exceptions. You are responsible for ordering the correct tube type.
TUBES ARE NOT EXCHANGEABLE OR REFUNDABLE UNDER ANY CIRCUMSTANCES Acceptance of our policies,
known or unknown to you, is acknowledged by your tube purchase.
We have very limited stocks on this tube as the Ei factory ain't makin' any more tubes. Please call or email
first to confirm availability.
90-DAY WARRANTY Defective tubes will be replaced with like items only; carefully read the Warranty Policy
for exceptions. You are responsible for ordering the correct tube type.
TUBES ARE NOT EXCHANGEABLE OR REFUNDABLE UNDER ANY CIRCUMSTANCES Acceptance of our policies,
known or unknown to you, is acknowledged by your tube purchase.
We have very limited stocks on this tube as the Ei factory ain't makin' any more tubes. Please call or email
first to confirm availability.
Hello canonken,
been playing with those amps, and modding them for a long time.
Try the Rusky 6n14p-ev. Really a 7189 tube, but plays extremely well in EL84 circuits.
You will not be disappointed ( I love them )
They've gotten a little pricey as of late.
I've got a bunch. Will sell you whatever cheap.
Or, if you want to try first, I'll send you a pair to play with. Postage both ways on you.
Cheers, Crazy Bill
been playing with those amps, and modding them for a long time.
Try the Rusky 6n14p-ev. Really a 7189 tube, but plays extremely well in EL84 circuits.
You will not be disappointed ( I love them )
They've gotten a little pricey as of late.
I've got a bunch. Will sell you whatever cheap.
Or, if you want to try first, I'll send you a pair to play with. Postage both ways on you.
Cheers, Crazy Bill
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6P14P = 6BQ5 to Google USA, the translations mix me up all the time. The Russian letter that looks kind of like an upside down upper case squared off "U" translates to "P" if goolgling. If you look for 6n14p its a small voltage tube on the web.
canonken,
Send the bad tubes back.
If you paid with a Visa or Master Card . . . Get your money back.
It does not matter that the web site said no returns.
Did you pay with Pay Pal? . . . I do not know if Pay Pal has that same refund policy that Visa and Master Card have.
Then, go to Eurotubes.com, and order some JJ EL84 tubes from them.
They re-test all the tubes they get from JJ in Slovakia.
I get all my current production tubes (all JJ) from Eurotubes.com
I just drive over and pick them up (I am in the same metro area in Oregon).
Those Eurotubes JJ tubes work for me.
Send the bad tubes back.
If you paid with a Visa or Master Card . . . Get your money back.
It does not matter that the web site said no returns.
Did you pay with Pay Pal? . . . I do not know if Pay Pal has that same refund policy that Visa and Master Card have.
Then, go to Eurotubes.com, and order some JJ EL84 tubes from them.
They re-test all the tubes they get from JJ in Slovakia.
I get all my current production tubes (all JJ) from Eurotubes.com
I just drive over and pick them up (I am in the same metro area in Oregon).
Those Eurotubes JJ tubes work for me.
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rayma,
In your Post # 4, you said EL34.
Perhaps you were just using that as an example, but . . .
an EL34 is completely different from an EL84.
In your Post # 4, you said EL34.
Perhaps you were just using that as an example, but . . .
an EL34 is completely different from an EL84.
Remember, the Cyrillic alphabet derives from the Greek alphabet. The Π "squiggle" is the Greek letter pi.
I try to provide both the Cyrillic and transliterations, when dealing with Russian tubes. In the case of the nice 7189 equivalent, it's 6Π14Π-EB (6p14p-ev), which is also marketed as EL84M.
Another example of a Russian type is 6H23-EB (6n23p-ev), which is a very tough 6922 equivalent.
Notice the pattern; the "EB" suffix is a fairly reliable indicator of better tubes.
I try to provide both the Cyrillic and transliterations, when dealing with Russian tubes. In the case of the nice 7189 equivalent, it's 6Π14Π-EB (6p14p-ev), which is also marketed as EL84M.
Another example of a Russian type is 6H23-EB (6n23p-ev), which is a very tough 6922 equivalent.
Notice the pattern; the "EB" suffix is a fairly reliable indicator of better tubes.
All bad is nothing new. At one of my customers, the Physics Dept of a University, six analogue voltmeters from a highly respected source arrived, all out of calibration by the same amount.
They went back for a recal, the customer was happy in the end.🙂
They went back for a recal, the customer was happy in the end.🙂
For what its worth, Upscale Audio seems to have a very good reputation (even if you find the owner a bit incongruent with your personality). The tubes are burned in, tested, and measured - I could understand if I bought something from eBay randomly there could be issues.
Does your UFO2 amp have the current meters on the front? If so, how much current do the good tubes draw under normal operation?
Since this is a self biasing amp it would have been very telling to know how much current the bad/incompatible tubes were drawing.
The Decware schematic shews SV83s. The cathode connexions are slightly different than the EL84. Check it out. Not always plug-in compatible🙂
They show right around 40 mA on the stock tubes (the 6P15P-EB) and on the cheap JJ EL84. They also showed right around 40 mA on the Ei ones from Upscale. Like all within a few mA of each other...38-42 range.
I do not know about about what the meters are actually showing to know if that is good, bad, indifferent.