Tubes for Lumley ST-40 power amplifier?
I am still needing information on the types of input and phase splitter tubes. They can either be 12AX7, 12AU7 or 12AT7. These twin triodes I can try them out, But the Tube which is used as a screen regulator is the information I needed badly.
The ST-40 uses 4 EL34 tubes on the output stage.
The Tube (octal based) at the back of the Toroidal Power tranny is data I need. I assume this could be employed as a screen regulator. It got 6.3 volts filament at pins 2 and 7, The Grid (Pin 5) measures 307 VDC and pins 3 and 4 measures ( Plate and Screen) 480 VDC. Is this tube could be EL34 or 6550 or 6L6 ?
Your help is highly appreciated!
Thank You,
John
I am still needing information on the types of input and phase splitter tubes. They can either be 12AX7, 12AU7 or 12AT7. These twin triodes I can try them out, But the Tube which is used as a screen regulator is the information I needed badly.
The ST-40 uses 4 EL34 tubes on the output stage.
The Tube (octal based) at the back of the Toroidal Power tranny is data I need. I assume this could be employed as a screen regulator. It got 6.3 volts filament at pins 2 and 7, The Grid (Pin 5) measures 307 VDC and pins 3 and 4 measures ( Plate and Screen) 480 VDC. Is this tube could be EL34 or 6550 or 6L6 ?
Your help is highly appreciated!
Thank You,
John
Tubes for Lumley ST40 power amplifier
Thanks Alain,
The ST70 uses 6650 and the ST40 uses EL34. The input and phase splitters are ECC82 and ECC83.
I am still uncertain about the octal based tube employed as a screen regulator located at the back of the toroidal power tranny. It could be an EL34 or a 6550?
Help anyone!
John
Thanks Alain,
The ST70 uses 6650 and the ST40 uses EL34. The input and phase splitters are ECC82 and ECC83.
I am still uncertain about the octal based tube employed as a screen regulator located at the back of the toroidal power tranny. It could be an EL34 or a 6550?
Help anyone!
John
Re: Tubes for Lumley ST40 power amplifier
hi john,
perhaps you mean the ST70 uses EL34's while the ST40 uses 6550 which can use screen regulators, well, another 6550 for screen regulator will not be a bad idea, but a 6as7/6080 will be better, error amps used 9pin miniatures? plus a discharge type vr regulators right?
john said:
hi john,
perhaps you mean the ST70 uses EL34's while the ST40 uses 6550 which can use screen regulators, well, another 6550 for screen regulator will not be a bad idea, but a 6as7/6080 will be better, error amps used 9pin miniatures? plus a discharge type vr regulators right?
Tubes for Lumley ST-40 power amplifier?
Thank you for the information Arnold!
Hi Tony,
Lumley ST70 uses 6550 as an output tubes, while the ST40 uses EL34 as output tubes. It's puzzling for me since what tube should I use to the another octal socket which is employed as a screen regulator, since the Bplus is solidstate rectified. I am considering of plugging in on the either 6550 or EL34 if I can't source the schematic diagram or any information on the tubes that were employed on this rare amplifier.
Based on the voltages I have given above, what tube would fit the as a screen regulator?
John
Thank you for the information Arnold!
Hi Tony,
Lumley ST70 uses 6550 as an output tubes, while the ST40 uses EL34 as output tubes. It's puzzling for me since what tube should I use to the another octal socket which is employed as a screen regulator, since the Bplus is solidstate rectified. I am considering of plugging in on the either 6550 or EL34 if I can't source the schematic diagram or any information on the tubes that were employed on this rare amplifier.
Based on the voltages I have given above, what tube would fit the as a screen regulator?
John
Tubes for Lumley ST-40 power amplifier?
Hi Guys,
Ben Carter replied.He said that based on the serial # I emailed him, What I have is an issue #2 which were designed to accomodate five 5881 / 6L6WGC power tubes. One of which is a power regulator. The input tubes are ECC82 and the phase splitters are ECC83.
Thank you Arnold and Tony for the much needed help! And to the rest of the guys!
God Bless and More Power!
John
Hi Guys,
Ben Carter replied.He said that based on the serial # I emailed him, What I have is an issue #2 which were designed to accomodate five 5881 / 6L6WGC power tubes. One of which is a power regulator. The input tubes are ECC82 and the phase splitters are ECC83.
Thank you Arnold and Tony for the much needed help! And to the rest of the guys!
God Bless and More Power!
John
Hi John
Just registered on this site so I can respond. I've just bought and had serviced a Lumley st40/pp40 combination. The later model PP40 was designed to use 6L6GCC's in the output stages as well as for the voltage regulator. The drivers and phase splitters are ECC62/63's but be careful to get these in the correct order (mine weren't!) . Apparently a great alternative to the 6L6's are to substitute good quality KT66's. Its debatable whethjer this will give much improvement though due to the high quality of the amp as a whole (they dont build them like this any more unless you're willing to mortgage your house for new esoteric kit). My amp was serviced and checked by Mike Soloman of London Sound (see website) who informs me that its a high quality valve amp benefitting from over engineering and is exceptionally stable in operation.
Current value in the UK for the st40 control unit plus pp40 amp is about £1200 to £1500 in good condition. Ben Carter's your man for detailed information and I note his email address is contained elsewhere on the thread. Hope this is of some help
Paul
Just registered on this site so I can respond. I've just bought and had serviced a Lumley st40/pp40 combination. The later model PP40 was designed to use 6L6GCC's in the output stages as well as for the voltage regulator. The drivers and phase splitters are ECC62/63's but be careful to get these in the correct order (mine weren't!) . Apparently a great alternative to the 6L6's are to substitute good quality KT66's. Its debatable whethjer this will give much improvement though due to the high quality of the amp as a whole (they dont build them like this any more unless you're willing to mortgage your house for new esoteric kit). My amp was serviced and checked by Mike Soloman of London Sound (see website) who informs me that its a high quality valve amp benefitting from over engineering and is exceptionally stable in operation.
Current value in the UK for the st40 control unit plus pp40 amp is about £1200 to £1500 in good condition. Ben Carter's your man for detailed information and I note his email address is contained elsewhere on the thread. Hope this is of some help
Paul
More Lumley Help Needed
I also have a Lumley ST-40, it has five 6L6 tubes, and the ECC82 inputs, ECC83 phase splitters, I had removed the valves while the amp was in storage for a while, and have lost the little sketch I made of the order the 83's and 82's go in, can someone tell me the sequence I should have them from left to right, or what valves go at the outside ?
Many Thanks
Rob
I also have a Lumley ST-40, it has five 6L6 tubes, and the ECC82 inputs, ECC83 phase splitters, I had removed the valves while the amp was in storage for a while, and have lost the little sketch I made of the order the 83's and 82's go in, can someone tell me the sequence I should have them from left to right, or what valves go at the outside ?
Many Thanks
Rob
Thanks Pacman, I had also been in touch with Metropolis Music in London, and for anyone else looking for info on the Lumley ST40 valve arrangement the information I gained may be of some help.(or further confusion)
At some point during the production of these amps, Lumley accually changed the 82's and 83's around, so it accually depends on the serial number of the amplifier !
At some point during the production of these amps, Lumley accually changed the 82's and 83's around, so it accually depends on the serial number of the amplifier !
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