I have used 6N5S's, and i think they are exactly the same with basic 6N13S.

I have build new amp. Just basic stereo amplifier without headphone connection. 470uF 450v capacitor is shared to both channels. All transformers and choke is from old Hammond organ amplifiers. Output transformers are originally for bass, but they seem to work excellent as full range...

Russian 6F6S's.

I have finished my newest DIY amp. Sadly no headphone connect (yet?). I bought Russian 6F6S tubes because of this effect. With 6F6S's around 2x13w triode connected and pentode connected 2x18w. So these small powertubes are giving their max. Of course this amp is designed for KT88's, and with...

Haven't been resting much with my diy amps. Here is phono preamp for MM cartridges. Followed this schematic http://www.hagtech.com/pdf/cornetoctal.pdf. Rectifier is 6X5 in my amp. Somehow this was rather tricky to make quiet. There is 2 6SL7s triodes doing their best to amplify signal in series...

I haven't been active at all here.    At last i got my own simple emission tube tester. Superior Instrument Co. TV-11. It needed just a little service and now it works like new and can test all my tubes. Since it is just emission tester, it's not very scientific or absolutely accurate. However...

I do not know if i have missed something here. It just have been too busy and no much time to "roll tubes". So happy with two of my latest DIY amps. One with TEN 6SL7GT and 6N6P-IR-s and another one with Russian reflector made 6N9S '86, 6N8S's '65 and 6N13S's from '74. All other tubes have been...

  Now this is another real problem to use 6AS7's as powertube with LD. With 150ohm cathode resistors 6AS7 could hog 4-5 times the current what 6N6P uses! I think LD does not have enough anode current. And LD resistors can't stand the heat. Cathode resistors should be 10W.   When coming to...

If i remember correctly LD can push 2.5A for powertubes, and 1.5A x 2 = 3A. Not recommended without external supply. 

I can use even 6AS7 tubes as driver with my little DIY amp. With RCA 6AS7G sound is excellent, BUT gain is very low, due to amp factor 2. So with low sensitivity headphones there could be problems to get enough power.   I suggest to use 6BL7 with amp factor 15 or 6BX7 amp factor 10. These...

5V on the plate?  No wonder if there is easily distortion. It's a miracle that it is possible to get any sound through with voltages like that. And i have been thinking, that under 50v between plate and cathode is no good.

  www.head-fi.org/t/563884/little-dot-tube-amps-vacuum-tube-rolling-guide/3795#post_9952269 I did use happily 3 octals with my LD mk2 over 100 pages ago.

Russian 1x 6N9S, 2x 6N8S, 2x 6N13S and one sylvania 6BY5GA. After photo 6N8S's have changed to older '65 model. It is stereo amplifier with headphone out too. First tube is for signal amplify only and second works as phase splitter too, so powertubes do things in push-pull.   With this amp i...

Now this is starting to look like a Tube Amplifier to me. Excellent!   But there is still some way to go. ~15kg

Not so common tube in this thread.

It works \o/ !    Newer 6BY5GA rectifier tube does not look that bad. It does have pretty strong glow. I also have older coke bottle model 6BY5G.   There is relay that disables speakers, if headphones are inserted. I have to be careful not to burn my headphones accidentally, this amp is...

Some progress. Don't know where camera found that greenish color...   I left some space for future improvements, like another RCA line in and more switches. Tomorrow i could begin soldering parts inside with my 15y old cheap soldering iron and that is much more fun than making chassis with...

Building new amp. Weights already over 10kg. Power Transformer is from that rather ugly 6SN7-6AS7 amplifier. With this amp that transformer looks much better. Still waiting for 6BY5G rectifier tube. RCA 6SN7GT tube is just there for photography. This is going to be "normal" stereo amplifier...

Those directly heated could be very very difficult to get work with LD. I could suggest next tubes: http://www.radiomuseum.org/tubes/tube_6j5g.html Half of the 6SN7, so you need 4 tubes to replace two 6N6P. http://www.radiomuseum.org/tubes/tube_6f8g.html Like 6SN7, but needs different adapter...

  Usually those jerry cans smell like diesel for a long time. But i have plans to do normal stereo tube amplifier with headphone output. It is little bit different to work with output transformers, but we'll see what is going to happen.

Heater voltages should be biased over cathode voltage. So between heater + and - is 6.3v, but minus side from amplifier zero should be more than cathode voltage. Otherwise with some tubes cathode starts to draw electrons from filament. Do not know is it even possible to raise voltages above...

I heard you were talking about using 6SN7 as powertube. This was my totally hum and noise free adapter for octals, made some months ago. With 6SN7 you lose some maximum power to headphones, but otherwise they work like charm. Btw Ten 6SL7GT tube is not bad at all. Been burning it in for some...

Here is indicative graphs for HD-330 and beyerdynamic DT-990 pro. Measured with bad equipment, so not accurate, but shows biggest differences with bass. Surprisingly DT-770 and DT-990 pro earpads are totally different sounding. They look like same, but material inside is different. So if one...

Good that someone with better testing equipment will post frequency response curves. Bought beyerdynamic DT-990 pro's. We'll see how they compare...

Here is an example what kind of driver tubes i am using with my DIY amp, that uses 6N6P powertubes. http://www.head-fi.org/t/698282/my-diy-headphone-tube-amps#post_10255710   I think that RCA 6AS7G is going to stay many hours on this amp.