I'm ordering a couple of 6c45pi.
What's the going controversy over these tubes? According to spec, these things are miracle tubes! High gain and low plate resistance triode.
With 150V and 35mA (7 watts on the plate), not a bad deal....
If you've heard or built using a 6c45pi, please post your comments.
What's the going controversy over these tubes? According to spec, these things are miracle tubes! High gain and low plate resistance triode.
With 150V and 35mA (7 watts on the plate), not a bad deal....
If you've heard or built using a 6c45pi, please post your comments.
You might find some interesting info here.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=10595&highlight=
happy new year
http://www.diyaudio.com/forums/showthread.php?s=&threadid=10595&highlight=
happy new year
Konnichiwa,
Not sure what the "going controversy" is. Like with any Valve, the 6S454 needs to employed intelligently to sound good. It has two peculiarities, one a very large sample to sample variation making pair matching mandatory and secondly a tendency to oscillate (like any High Gm Valve), which requires some care in implementation.
Sayonara
Kashmire said:
Not sure what the "going controversy" is. Like with any Valve, the 6S454 needs to employed intelligently to sound good. It has two peculiarities, one a very large sample to sample variation making pair matching mandatory and secondly a tendency to oscillate (like any High Gm Valve), which requires some care in implementation.
Sayonara
I’ve heard two reports about some of the Russian “super tubes” like the 6C45pi. The detractors say it sounds like solid-state; really dry. The admirers say the incredible performance and versatility makes it a great candidate for new designs.
Both may be true. It may be a high-performance tube that sounds like solid-state.
I intend to listen to a 6C45pi – but it requires laying out a whole new circuit, when I’ve already got a lot going on. I wanted opinions from people who have already tried it.
Both may be true. It may be a high-performance tube that sounds like solid-state.
I intend to listen to a 6C45pi – but it requires laying out a whole new circuit, when I’ve already got a lot going on. I wanted opinions from people who have already tried it.
Hi,
O.K...My New Year gift to you:
The latter party is right and as Thorsten said, it needs some precautions to use.
Mostly gridstopper all over the place and careful selection.
Other than that it's a godsend..............
Get a dozen,
P.S. There are some other ex-USSR tubes you'd care to learn about....
Cheers,
O.K...My New Year gift to you:
The latter party is right and as Thorsten said, it needs some precautions to use.
Mostly gridstopper all over the place and careful selection.
Other than that it's a godsend..............
Get a dozen,
P.S. There are some other ex-USSR tubes you'd care to learn about....
Cheers,
I admit, I'm a bit of a noobie.
At building with tubes, that is. I've spent a decade of doing calculations, working equations, plotting load lines, and drawing schematics, but never built anything.
I'm a changed man. I've been building like a lunitic for a couple months, changing my ways and redeeming my past. All those schematics that I've drawn for the last couple years are becoming real hardware.
My latest batch includes tubes suitable to drive the Lundahl LL1660s/18mA interstage transformer. Darn! Why didn't I get a higher current interstage to try the 6c45pi?
My latest efforts use the 7788/E810F or 5965 to drive the interstage. In turn, the interstage drives Tung-sol 6550 or JJ KT-88 grids. I'm an aspiring roller, so I can't wait for my EL34s.
Now that you know this, what's the rest of the russian super-tubes out there?
At building with tubes, that is. I've spent a decade of doing calculations, working equations, plotting load lines, and drawing schematics, but never built anything.
I'm a changed man. I've been building like a lunitic for a couple months, changing my ways and redeeming my past. All those schematics that I've drawn for the last couple years are becoming real hardware.
My latest batch includes tubes suitable to drive the Lundahl LL1660s/18mA interstage transformer. Darn! Why didn't I get a higher current interstage to try the 6c45pi?
My latest efforts use the 7788/E810F or 5965 to drive the interstage. In turn, the interstage drives Tung-sol 6550 or JJ KT-88 grids. I'm an aspiring roller, so I can't wait for my EL34s.
Now that you know this, what's the rest of the russian super-tubes out there?
Hi,
There are a couple but here are the ones that amaze the world:
6C19P, close to the TFK ED 8000.
6C41P, close to halve the famous Mig tube 6C33C.
6H1P, some 6DJ8 but far from equivalent.
6H30P, BAT's favourite....
There's more, much, much more....keep'em alive by buying them.
BTW, I hear Svetlana is in big trouble since their last adventure into the U.S...
Nobody wants them to fade into history....
Cheers
There are a couple but here are the ones that amaze the world:
6C19P, close to the TFK ED 8000.
6C41P, close to halve the famous Mig tube 6C33C.
6H1P, some 6DJ8 but far from equivalent.
6H30P, BAT's favourite....
There's more, much, much more....keep'em alive by buying them.
BTW, I hear Svetlana is in big trouble since their last adventure into the U.S...
Nobody wants them to fade into history....
Cheers
The One tube design page feactures a few circuites using this
tube.
http://digilander.libero.it/paeng/one_tube_design_page_CIRCUITES.htm?
Woody
tube.
http://digilander.libero.it/paeng/one_tube_design_page_CIRCUITES.htm?
Woody
Konnichiwa,
Using the 6S45 at 18mA is fine, trust me. I prefer even lower anode currents, make the anode current too high and the sound of ANY High Gm Valve I have played with becomes hard and steely, pretty much that kind of sound people have criticised in the 6S45 when used as driver valve, simply because they acted on the idea "if it's rated at 50mA Max I must operated it at 60mA!".
Triode Wired E810F sounds better than 6S45 but is harder to find and not in current production. BTW, the E180F is in current production and makes a good "pseudo 417A".
Given the ridiculous rises in price since the "well known" super valves such as 6N6, 6N30 and 6S45 became known in the west you must forgive the cognescenti for not divulging the Numbers of the real sleepers still languishing in Stores from the cold war in Russia. We used to buy the 6S45 for around 6 Bucks each, landed cost (inclusive shipping, taxes and duties!) before they became fashionable.
Sayonara
Kashmire said:
Using the 6S45 at 18mA is fine, trust me. I prefer even lower anode currents, make the anode current too high and the sound of ANY High Gm Valve I have played with becomes hard and steely, pretty much that kind of sound people have criticised in the 6S45 when used as driver valve, simply because they acted on the idea "if it's rated at 50mA Max I must operated it at 60mA!".
Kashmire said:
Triode Wired E810F sounds better than 6S45 but is harder to find and not in current production. BTW, the E180F is in current production and makes a good "pseudo 417A".
Kashmire said:
Given the ridiculous rises in price since the "well known" super valves such as 6N6, 6N30 and 6S45 became known in the west you must forgive the cognescenti for not divulging the Numbers of the real sleepers still languishing in Stores from the cold war in Russia. We used to buy the 6S45 for around 6 Bucks each, landed cost (inclusive shipping, taxes and duties!) before they became fashionable.
Sayonara
Hi Guys
I was running three NOS RCA Blackplate 5963s in parallel (six triodes) per channel in a plate loaded triode config before ripping it all out and trying the 6C45pi. Despite having very nice components (remote PSU with dual mono transformers, Shallcos, BGate caps, corian box, etc) the bass was a bit shy and it lacked dynamics compared to my EAD processor...it was also pretty microphonic.
I've now got two of the 6Cs in there alone, and I am very impressed with the results. 170V plate voltage (higher than spec but told this is OK, check the size of the plates out!), 40mA current (must try lower currents later based on the last reply, thanks!), 47R cathode with 220uf bypass. I used 100R AND ferrite on lead to grid and interconnected grids with a ferrite on the lead also. No oscillation problems at all. Bass is heaps better, dynamics are incredible and there is more gain than I know what to do with. The non microphonic nature of the tubes is also excellent.
I have been trying different heater voltages also, and seem to prefer higher than 6.3V than lower. YMMV. This counteracts the slight brightness that is mentioned earlier in this post. It seems more fleshed out at say 6.5V I believe.
Well worth trying guys, IMHO and cheap too
Cheers, Kendrick
I was running three NOS RCA Blackplate 5963s in parallel (six triodes) per channel in a plate loaded triode config before ripping it all out and trying the 6C45pi. Despite having very nice components (remote PSU with dual mono transformers, Shallcos, BGate caps, corian box, etc) the bass was a bit shy and it lacked dynamics compared to my EAD processor...it was also pretty microphonic.
I've now got two of the 6Cs in there alone, and I am very impressed with the results. 170V plate voltage (higher than spec but told this is OK, check the size of the plates out!), 40mA current (must try lower currents later based on the last reply, thanks!), 47R cathode with 220uf bypass. I used 100R AND ferrite on lead to grid and interconnected grids with a ferrite on the lead also. No oscillation problems at all. Bass is heaps better, dynamics are incredible and there is more gain than I know what to do with. The non microphonic nature of the tubes is also excellent.
I have been trying different heater voltages also, and seem to prefer higher than 6.3V than lower. YMMV. This counteracts the slight brightness that is mentioned earlier in this post. It seems more fleshed out at say 6.5V I believe.
Well worth trying guys, IMHO and cheap too
Cheers, Kendrick
Thanks for the tip, just wish I had a CRO to verify.... Fortunately I do have access to one occasionally so I'll investigate further.
Interestingly enough, when I tried the 82R/68uf cathode R/C combo the plate voltage went up which I thought was unexpected (from 47R/220uf). Can someone explain this? I was hoping to simulate in TubeCAD but the tube isn't in the database and I don't seem able to add the 6c to it either.
Also this new R\C combo did lead to oscillation in the right channel. Major bummer
I have seen about a 10V difference in plate voltage between the channels which I assume comes back to the unmatched tubes.
Cheers, Kendrick
Fortunately I do have access to one occasionally so I'll investigate further.Interestingly enough, when I tried the 82R/68uf cathode R/C combo the plate voltage went up which I thought was unexpected (from 47R/220uf). Can someone explain this? I was hoping to simulate in TubeCAD but the tube isn't in the database and I don't seem able to add the 6c to it either.
Also this new R\C combo did lead to oscillation in the right channel. Major bummer
I have seen about a 10V difference in plate voltage between the channels which I assume comes back to the unmatched tubes.
Cheers, Kendrick
6C45pi is a cracking little valve with super linearity, but it needs care to stop it oscillating at VHF. Decouple the HT locally, use a carbon-film grid-stopper, and if you use it as a cathode follower, add a cathode-stopper. It needs a bit of current to wake it up, but 15mA is quite sufficient. I don't believe the 7.8W rating from that envelope at normal temperatures, although a gentle draught of air at -50C (temperature at 50,000 feet) would comfortably enable the rating.
Hi and thanks for the tips EC8010...
I decoupled the HT (1000pf/1000V ceramic) and also removed the inter grid wire with ferrite I added earlier. I then added a ferrite on the cathode lead as well, and it seems to have cured the oscillations using the 82R/68uf cathode R/C combo (at least for the last five minutes I've been listening to it!)
I decoupled the HT (1000pf/1000V ceramic) and also removed the inter grid wire with ferrite I added earlier. I then added a ferrite on the cathode lead as well, and it seems to have cured the oscillations using the 82R/68uf cathode R/C combo (at least for the last five minutes I've been listening to it!)
Early days yet to say how it sounds, but when it was oscillating it seemed to have lower output in the channel that I believe was oscillating. Now they seemed better matched which is obviously a good thing. Dave Weckl live sounds pretty good...
fdegrove, your brief feedback is appreciated but why not share your knowledge with the team please...forgive me, I'm trying to learn here.
The ferrites chosen were the Nickel/Zinc type catalog no 232-9628 in RS Components, page 922 of the Aussie catalog - these have a 49dB attenuation at 10Mhz, 72 at 25Mhz and 101dB at 100Mhz...if you are implying that this limits the bandwidth are you suggesting these will attenuate in the audible frequency range if used on the cathode or grid leads? Without a curve of their attenuation in the kHz range or a cro handy it's hard to verify...
Keep the good ideas flowing guys...
fdegrove, your brief feedback is appreciated but why not share your knowledge with the team please...forgive me, I'm trying to learn here.
The ferrites chosen were the Nickel/Zinc type catalog no 232-9628 in RS Components, page 922 of the Aussie catalog - these have a 49dB attenuation at 10Mhz, 72 at 25Mhz and 101dB at 100Mhz...if you are implying that this limits the bandwidth are you suggesting these will attenuate in the audible frequency range if used on the cathode or grid leads? Without a curve of their attenuation in the kHz range or a cro handy it's hard to verify...
Keep the good ideas flowing guys...
Sound comments as-is
Nitin Sawhney - Migration - Tk 1 - excellent depth. Voice is very airy and natural sounding. Bass may be a touch plummy, but has wonderful texture (and is synthesized so hard to know what it is meant to sound like). No oscillation and nicely centred image. Tabla is nicely palpable - there's a lot to like...
Nitin Sawhney - Migration - Tk 1 - excellent depth. Voice is very airy and natural sounding. Bass may be a touch plummy, but has wonderful texture (and is synthesized so hard to know what it is meant to sound like). No oscillation and nicely centred image. Tabla is nicely palpable - there's a lot to like...
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