OK, I tried some Russian army 6P14P El84 subs. I got 7 "new" tubes that look like pulls to me. Anyway, I keep blowing the same tube position ??? The volume drops off, and the tube lights up with the death glow. Swapped a bunch of tubes, same deal but I didn't let them get to the death glow.
I have a set of Sovtek's in there, and no problems at all.
Secondly, I tried some 6N2P-EV 12ax7 subs. These looked brand new, but out of the 4 I got, zero work.
Anybody have any sugestions???
CR
PS Amp is a TMB
Russian Tube Blues
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Brewmaster
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First off keep in mind most tube guys burn in their tubes before they sell them to make sure they are good. They probably aren't pulls if you bought from a reputable source.
I have 5 pair of NOS 6n14n that I got from SGT Overdrive. I put sets 3 in three different amps for some local working musicians and a set in my 18 watter and have had no issues. In fact just the opposite, they sound better than any current production tube I have tried and give my hex plate Teslas a run for the money.
Are you sure the 6P14P is a direct replacement for an el-84?
Edited to add: I just did some searches and found that some sites are selling the 6P14P as EL84M/6P14P, current production Sovteks. Are these what you have?
I have 5 pair of NOS 6n14n that I got from SGT Overdrive. I put sets 3 in three different amps for some local working musicians and a set in my 18 watter and have had no issues. In fact just the opposite, they sound better than any current production tube I have tried and give my hex plate Teslas a run for the money.
Are you sure the 6P14P is a direct replacement for an el-84?
Edited to add: I just did some searches and found that some sites are selling the 6P14P as EL84M/6P14P, current production Sovteks. Are these what you have?
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ny_racer_xxx
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ny_racer_xxx
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Matching EL84's
I came across some really good trouble shooting info that included basically match a set of tubes.
It was on the amp maker website.
I created a excell spread sheet to do all the calculations. I used one tube at a time in my TMB. What you measure is pin3 Cathode voltage, pin7 Plate voltage, and pin9 Grid voltage. Also you measure across the resistor that drops the voltage for screens (r40) in my amp, and divide by the resitor value to calculate the screen current draw.
From this info I got cathode current, screen current, plate current and plate dissapation.
On the top of my sheet is the Russian 6P's and you can see how all over they are and that 3 are basically dead.
The lower section is a match set of Sovteks, that are pretty well matched.
CR
OK how do I attach a file in this forum?
It was on the amp maker website.
I created a excell spread sheet to do all the calculations. I used one tube at a time in my TMB. What you measure is pin3 Cathode voltage, pin7 Plate voltage, and pin9 Grid voltage. Also you measure across the resistor that drops the voltage for screens (r40) in my amp, and divide by the resitor value to calculate the screen current draw.
From this info I got cathode current, screen current, plate current and plate dissapation.
On the top of my sheet is the Russian 6P's and you can see how all over they are and that 3 are basically dead.
The lower section is a match set of Sovteks, that are pretty well matched.
CR
OK how do I attach a file in this forum?
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dotfret
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To avoid confusion -
The best convention is to use the lower case letters to represent th cyrillic characters. To discuss this, we need to use p = the Greek letter pi, P in Cyrillic, e = E in cyrillic, v = B in cyrillic, r = P in cyrillic, d = a sort of squiggly A shape in cyrillic.
Generally, 6p14p are a good replacement for EL84, and sound better than new production.
Variants that you can find - you get 6p14p-e (e means rugged construction), 6p14p-ev (v means military, and usually means slightly higher heater current, but low noise), 6p14p-er (r is low noise) and 6p14p-dr (d is 10,000 hr lifetime test - the real EL84M clone).
All these usually work as replacements for EL84 with no problems.
But Russians will often tell slight untruths when selling valves -examples - 6n1p are often sold as equivalent to 6DJ8, but the Russian valve draws twice as much heater current - and there are some Russian 6p3s valves which are exact replacements for 6L6GC, whereas others are exact replacements for 6L6G, and others are a Russian design that can substitute for 6L6G, but will redplate if you put them in place of 6L6GC. They are all marked 6p3s - and Joe Moskovitch, your road sweeper vendor, has some 6p3s valves, limited English, and previous eBay listings for reference - caveat emptor!
Knowing that many Russian valves are misdescribed when sold, it would not surprise me to find that you have either been sold a Russian EL86 equivalent, and they will not stand up to the B+, or some other pentode that has a lower power handling capacity.
I have used a lot of 6p14p, and in my experience they just wear out, very slowly.
If theyare unmarked, or only have marks in blue ink, I would be very suspicious if I did not know the vendor ...
The best convention is to use the lower case letters to represent th cyrillic characters. To discuss this, we need to use p = the Greek letter pi, P in Cyrillic, e = E in cyrillic, v = B in cyrillic, r = P in cyrillic, d = a sort of squiggly A shape in cyrillic.
Generally, 6p14p are a good replacement for EL84, and sound better than new production.
Variants that you can find - you get 6p14p-e (e means rugged construction), 6p14p-ev (v means military, and usually means slightly higher heater current, but low noise), 6p14p-er (r is low noise) and 6p14p-dr (d is 10,000 hr lifetime test - the real EL84M clone).
All these usually work as replacements for EL84 with no problems.
But Russians will often tell slight untruths when selling valves -examples - 6n1p are often sold as equivalent to 6DJ8, but the Russian valve draws twice as much heater current - and there are some Russian 6p3s valves which are exact replacements for 6L6GC, whereas others are exact replacements for 6L6G, and others are a Russian design that can substitute for 6L6G, but will redplate if you put them in place of 6L6GC. They are all marked 6p3s - and Joe Moskovitch, your road sweeper vendor, has some 6p3s valves, limited English, and previous eBay listings for reference - caveat emptor!
Knowing that many Russian valves are misdescribed when sold, it would not surprise me to find that you have either been sold a Russian EL86 equivalent, and they will not stand up to the B+, or some other pentode that has a lower power handling capacity.
I have used a lot of 6p14p, and in my experience they just wear out, very slowly.
If theyare unmarked, or only have marks in blue ink, I would be very suspicious if I did not know the vendor ...
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