hello 🙂
friend gave me some tubes from an amp he had serviced years ago.
YAY i say! first glance, i have some spare 6bq5's!
they have no label...
well. they are NOT what i expected.
one small, minor, tiny, insignificant difference...
g2 is on pin 1.
pin 9 is just a support for the mica insulation.
so, erm...what exactly ARE these things?
theres that many million numbers i could be searching for the rest of my life...
thanks peoples with more brains than me 🙂
friend gave me some tubes from an amp he had serviced years ago.
YAY i say! first glance, i have some spare 6bq5's!
they have no label...
well. they are NOT what i expected.
one small, minor, tiny, insignificant difference...
g2 is on pin 1.
pin 9 is just a support for the mica insulation.
so, erm...what exactly ARE these things?
theres that many million numbers i could be searching for the rest of my life...
thanks peoples with more brains than me 🙂
cheers for the quick response, but no prizes yet...
6ce5 is a septal base (7 pin)
el86 has same pinouts as el84.
the ONLY difference with what i have here, is g2 being on pin 1 rather than 9.
not considering characteristics, of course...
6ce5 is a septal base (7 pin)
el86 has same pinouts as el84.
the ONLY difference with what i have here, is g2 being on pin 1 rather than 9.
not considering characteristics, of course...
Are you shure it's g2 on pin 1 and not g1 ?
The EL85 (or EL805) has pin 9 free but g1 on pin 1.
Mona
The EL85 (or EL805) has pin 9 free but g1 on pin 1.
Mona
If it is made by Philips there should be a code etched in the glass close to the pins.
You can look that one up to see what it is.
EL83 would be my prime suspect. Etch code mU, T4 or fL.
Can you post a photo?
You can look that one up to see what it is.
EL83 would be my prime suspect. Etch code mU, T4 or fL.
Can you post a photo?
ooooh, the 83 looks like it could be it....
right. i guess i need to set up a test bench to really check it out.
cheers peoples... im still open to suggestions though!
right. i guess i need to set up a test bench to really check it out.
cheers peoples... im still open to suggestions though!
I was thinking can it be 6GK6, almost same specs and outer look as EL84, but different pinout. Nevertheless G1 is still pin2
hmmm, not so easy to find a data sheeet and most references say theyre pretty poxy anyway...
i have a feeling this was from his "moody blues" amp, being australian and all that gaf.
might suggest modifying it to suit the el84.... if it wasnt already done. never thought of looking INSIDE his amp now, did i?
now i feel like ive wasted everyones time 🙁
nah, knowledge is useful. any knowledge 🙂
i have a feeling this was from his "moody blues" amp, being australian and all that gaf.
might suggest modifying it to suit the el84.... if it wasnt already done. never thought of looking INSIDE his amp now, did i?
now i feel like ive wasted everyones time 🙁
nah, knowledge is useful. any knowledge 🙂
The EL80/6M5 is ~90% of an EL84, plate dissipation of 10 watts, not 12, and need to be a little cautious of screen voltage. Perfectly useable in EL84 designs though if limits respected. If you have a bunch, light them up, they will be nicely made tubes from Philips Hendon plant, made with Mullard dies (and prob the internals).
woo hoo! more knowledge!
yesh, ok, point taken, they would be good for say, my lil 5 watt stereo...
i happen to have a teisco checkmate 25 here. 7189 rather than el84. and boy, is it woeful!
it works but absolutely no get up and go in it. part of the problem i believe is that its biased way too cold for the el84 to break past 8 watts. even in PP! but the whole amp is a waste of time... transformers are side by side, the reverbs tiny, and and and and ad nauseum.
i was sorta hoping id have something closer to the 7189 tube here, but no such luck.
but...i have just come across the "traynor guitar mate"
compare schematics, if you will, and tell me what you think 😉
yesh, ok, point taken, they would be good for say, my lil 5 watt stereo...
i happen to have a teisco checkmate 25 here. 7189 rather than el84. and boy, is it woeful!
it works but absolutely no get up and go in it. part of the problem i believe is that its biased way too cold for the el84 to break past 8 watts. even in PP! but the whole amp is a waste of time... transformers are side by side, the reverbs tiny, and and and and ad nauseum.
i was sorta hoping id have something closer to the 7189 tube here, but no such luck.
but...i have just come across the "traynor guitar mate"
compare schematics, if you will, and tell me what you think 😉
An externally hosted image should be here but it was not working when we last tested it.
Last edited:
personally, i like the fact it only uses ecc83's rather than 82 or 81 etc, always annoying when dealing with mystery amps with unlabelled sockets.
so you think i should tear down the teisco? i sure do!
only issue now is whether to keep the tiny reverb or use the "cascade" brand i have here on the shelf.
so you think i should tear down the teisco? i sure do!
only issue now is whether to keep the tiny reverb or use the "cascade" brand i have here on the shelf.
Last edited:
Hmm, your Qs re the two different amps are prob more suited to the musical instrument forum, though I can observe that both designs run pretty high voltages for 7189/6BQ5 tubes.
AFAIK, current production tubes won't be happy, though some say the JJ EL84 will take the higher voltages. If going past plate voltage of 300, rather suggest cathode bias and a screen supply stabilised at 250. Am doing just that with a Tubelab SPP. Suggest to keep in mind total plate and screen dissipation, that little bottle won't like combined dissipation of more than 12 watts for reliability and useful life, whatever the voltages are.
AFAIK, current production tubes won't be happy, though some say the JJ EL84 will take the higher voltages. If going past plate voltage of 300, rather suggest cathode bias and a screen supply stabilised at 250. Am doing just that with a Tubelab SPP. Suggest to keep in mind total plate and screen dissipation, that little bottle won't like combined dissipation of more than 12 watts for reliability and useful life, whatever the voltages are.
Last edited:
This likely belongs on the instruments forum, but are you sure all the triodes are meant to be ECC83s? Just that the reverb driver and tremolo circuit, and perhaps the phase splitter looks an odd choice there, perhaps ?
yep. there may be a few tweaks going on while i build it, but basically...sovtek 84's are dirt cheap... and in the guitar world, we dont care how often they fry!
i think i paid 60 or so for matched quads. chickenfeed really. fry and die, fry and die... people have to buy them or the factories will shut down, wont they? and then what will we do?
sound? i want em distorted! i have an SE i made here thats pulling 11 watts from one and it puts the teisco to shame! everything about this teisco makes me ask...WHY??? or whats the other common expletive? WTF? 🙂
i do find sovtek 12ax7 sounds absolutely nasty though(base model, not a top-end one). so i use a mitsubishi in that particular amp. still have plenty to pick from before i feel the urge to buy any.
got a friend at a scrap yard that collects em for me as well... hes learning whats good and whats not. got me some nice vintage ceramic bases the other week 🙂
whereas the mullards i have in boxes still, from an elderly radio tech, purchased years ago...(not questionable nos...genuine nos!)theyre staying in the box or for hifi only. they might be better built/rated...but are irreplaceable in my opinion. that was a hard job... i could only take so many boxes home with me. a lot went to ... id rather not say. we were pulling the house down. go figure.
no, i dont. i sold most of them. sorry.
thanks for all the help, and that datasheet! some people really go out of their way... kudos 🙂 sometimes the world isnt as messed up as it appears.
i think i paid 60 or so for matched quads. chickenfeed really. fry and die, fry and die... people have to buy them or the factories will shut down, wont they? and then what will we do?
sound? i want em distorted! i have an SE i made here thats pulling 11 watts from one and it puts the teisco to shame! everything about this teisco makes me ask...WHY??? or whats the other common expletive? WTF? 🙂
i do find sovtek 12ax7 sounds absolutely nasty though(base model, not a top-end one). so i use a mitsubishi in that particular amp. still have plenty to pick from before i feel the urge to buy any.
got a friend at a scrap yard that collects em for me as well... hes learning whats good and whats not. got me some nice vintage ceramic bases the other week 🙂
whereas the mullards i have in boxes still, from an elderly radio tech, purchased years ago...(not questionable nos...genuine nos!)theyre staying in the box or for hifi only. they might be better built/rated...but are irreplaceable in my opinion. that was a hard job... i could only take so many boxes home with me. a lot went to ... id rather not say. we were pulling the house down. go figure.
no, i dont. i sold most of them. sorry.
thanks for all the help, and that datasheet! some people really go out of their way... kudos 🙂 sometimes the world isnt as messed up as it appears.
thats what the schematics say, either the original or that redrawn one.
havent seen anyone mention anything else on any of the reviews ive read so far. most owners seem quite happy with them though?
yes, is slightly unusual but hey... if they work, im not going to worry. just copy!
look! i posted in the tube section cus all i wanted was to know what those tubes i had were! now this thread is going off on a tangent- typing as i think helps me solidify any thoughts 🙂
its ok 🙂 i dont feel the need to start another thread just yet, even as this one draws to a close.
Bias ?
Ever thought about cathode biasing the power tubes...and perhaps going to a long tail phase inverter with perhaps 12at7 or 12ax7....( fender v marshal )
it would give you a more breaking , blues sound....perhaps at the cost of a couple of watts but your tubes would survive better, especially a nice set 😀
Ever thought about cathode biasing the power tubes...and perhaps going to a long tail phase inverter with perhaps 12at7 or 12ax7....( fender v marshal )
it would give you a more breaking , blues sound....perhaps at the cost of a couple of watts but your tubes would survive better, especially a nice set 😀
- Status
- Not open for further replies.