• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

6V6 line preamp

6g6g. Had to heat them heaters from a fluffy external supply since only 150 mA heaters. Microphonic this pair: medium high. Sound: up to you guys but I'm staying right here. Heavenly. Its small ST bottles. Lovely tubes.
 

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diyAudio Chief Moderator
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Awesome info Stajo, the 6V6 pre owners will dig it. Those ΡΑΔΗΟ Russian NOS are nice indeed. Maybe the 7V Vh higher temperature made them ding a dong a little more. I have some, sound is good in all but hiss may differ, they can be bit of a gamble if buying only two. I find them powerful enough yet "melodious". Good remedy for bad tweeterzzz.
 
You got 6K6 also? (the ones disco recommends)
On the ship. A full day of hard negotiating my *** off and a son with 39,5 C fever says this day is a done day. Even if I did win the negotiations;). I must say that this test is a bit unfair because my amp is high sensitive and the Focusrite Pro outputs more then enough rms for it. So everything I put inbetween is only gonna worsen the sound, and it does clearly. Furthermore its an untuned unisolated breadbord test rig but that taken in account its not bad that I still sit in the sofa with some of the samples. 6g6g I could almost let be there cause it colours very little. Lower mu also so... but anyway it was an interesting experiment.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
On the ship. A full day of hard negotiating my *** off and a son with 39,5 C fever says this day is a done day. Even if I did win the negotiations;). I must say that this test is a bit unfair because my amp is high sensitive and the Focusrite Pro outputs more then enough rms for it. So everything I put inbetween is only gonna worsen the sound, and it does clearly. Furthermore its an untuned unisolated breadbord test rig but that taken in account its not bad that I still sit in the sofa with some of the samples. 6g6g I could almost let be there cause it colours very little. Lower mu also so... but anyway it was an interesting experiment.
The valves and Metaxa took off the edge of the day I hope. ;)

High gain chain does not help the weaker constructed bottles but hey its more obvious test bed for ding and rattle so to know what to expect as better or not that good in any other gain scale. Maybe the 6G6G could be alright for echoes also when say in a normal gain normal sens speakers situation after all.
 
I've never seen a Philips 6V6. Could they come from Australia? Philips bought a production line down under in the 1940s.

Theres a first time for everyone isnt it? Well I'm not the biter of calendars but if you want tube history you can talk to the boat owner currently in hospital. Hold up almost any tube he'll tell you where its made, by whom, when and who branded it ADHD square
 

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Awesome info Stajo, the 6V6 pre owners will dig it. Those ΡΑΔΗΟ Russian NOS are nice indeed. Maybe the 7V Vh higher temperature made them ding a dong a little more. I have some, sound is good in all but hiss may differ, they can be bit of a gamble if buying only two. I find them powerful enough yet "melodious". Good remedy for bad tweeterzzz.

Got... ehum... to many. I could ofc try some samples out for the keen one. Did so for George.
 
Nice tubes. Is this pre in gain or in follower mode?

Same config actually. It was a gamble slipping them in. Started with 12,5 v on the filaments :)

Its 5 k load, can be higher and 320 from the sshvs. Silmic decouples and 680 on the cathode. Output couplers could shape up. Will post a pic of the mess from phone. Rebuilt it in 180 when I came home on the kitchen table.
 
diyAudio Chief Moderator
Joined 2002
Paid Member
Same config actually. It was a gamble slipping them in. Started with 12,5 v on the filaments :)

Its 5 k load, can be higher and 320 from the sshvs. Silmic decouples and 680 on the cathode. Output couplers could shape up. Will post a pic of the mess from phone. Rebuilt it in 180 when I came home on the kitchen table.

Its the common cathode circuit then.