My 807 are SE connected on UL tap of 5K:6ohm OPT, small 6db global feedback with B+ of about 400Vdc. I tried the russian 807 but didn't like them, my fav. is the RCA 807.
BR,
Eric
BR,
Eric
Do you built the amp?
How much W it sport?
How much hours has been last the 807 tube?
Yes,I did built the amp.
It's about 6W/ch.
Each tube is biased at 70mA, dissipation is at about 85% of max Pd.
807 are very though tube so they last long, using them for audio is a walk in the parc for them.
It's about 6W/ch.
Each tube is biased at 70mA, dissipation is at about 85% of max Pd.
807 are very though tube so they last long, using them for audio is a walk in the parc for them.
807's in push pull were used in some monaural record cutting amplifiers (Presto..) 807's are a good audio amplifier tube when run in AB1 push-pull.....many AM broadcast transmitters used 807's as modulator and RF drivers....
I built a PP amp with Russian G-807 tubes in triode mode, using 5k:8 transformer. It delivers 12.5W at 1% THD without global NFB, only cathode feedback.
How is the G807 sound in your amp?
How much hours these tubes has been lasts?
Thankyou
You might try the 6P3S which is a 6L6 equiv.
I run them in UL or Triode connection with 420V cathode to plate @ about 60ma. Yes that exceeds the specs but they don't glow, and they've been taking this abuse for 2 years now.
YMMV.
Cheers.
I run them in UL or Triode connection with 420V cathode to plate @ about 60ma. Yes that exceeds the specs but they don't glow, and they've been taking this abuse for 2 years now.
YMMV.
Cheers.
>>> How much W it sport?
>> It's about 6W/ch.
>> Each tube is biased at 70mA, dissipation is at about 85% of max Pd.
> Its 25W Pd, so 6W in UL is too little.
You may be confusing Output with Dissipation.
A SE tet/pentode can run maximum 'clean' Sine output about 40% of its dissipation.
e_ says he is running 85% of rated dissipation. Assuming 25W, this is 21W (about 300V 70mA). Assuming 40% of that, he "should" have 8.5W Output at about 5%-8% THD, if the loading and bias are just-right. So the "6W" figure is reasonable if e_ has measured at a lower THD point, or tuned load and bias for "sound" rather than maximum power.
Working a 42W 6550 at 39W, and trying different loads, I was able to get 13W Out pretty clean and 17W Out pretty bent. (24W clipped to near-square.) 13W out for 39W Pdiss is output 33% of dissipation; 17W out for 39W Pdiss is output 43% of dissipation.
>> It's about 6W/ch.
>> Each tube is biased at 70mA, dissipation is at about 85% of max Pd.
> Its 25W Pd, so 6W in UL is too little.
You may be confusing Output with Dissipation.
A SE tet/pentode can run maximum 'clean' Sine output about 40% of its dissipation.
e_ says he is running 85% of rated dissipation. Assuming 25W, this is 21W (about 300V 70mA). Assuming 40% of that, he "should" have 8.5W Output at about 5%-8% THD, if the loading and bias are just-right. So the "6W" figure is reasonable if e_ has measured at a lower THD point, or tuned load and bias for "sound" rather than maximum power.
Working a 42W 6550 at 39W, and trying different loads, I was able to get 13W Out pretty clean and 17W Out pretty bent. (24W clipped to near-square.) 13W out for 39W Pdiss is output 33% of dissipation; 17W out for 39W Pdiss is output 43% of dissipation.
I mean say 6 or 8W power output is little for my FR driver 94dB 8 ohms.
I would like min.10W or 12W from one 1625, I dont want pay KT88 prices.
There is no reliable info on 807/1625 time life.
ALso seems KT150 timelife is the usual 2k HOURS for 90USD😱
I would like min.10W or 12W from one 1625, I dont want pay KT88 prices.
There is no reliable info on 807/1625 time life.
ALso seems KT150 timelife is the usual 2k HOURS for 90USD😱
If that's the case you might consider parallel operation. I built a 6L6 (not GC) push pull parallel triode connected amp that puts out 17W <2% distortion. UL connection gets over 40W. Granted it's more of a pain in the *** to balance 4 tubes than 2 but much cheaper than KT88...
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do you really need a few extra W ? - the extra power isn't going to make it a much louder amplifier because our ears are logarithmic. You could spend a lot of effort when all you had to do was sit a couple of feet closer to the speakers 😎
I dont know kow much tube W I will need, but I will seat about 3 meters from the speakers as my room is small.
My speaker is the AN Classic10Alnico;
http://www.commonsenseaudio.com/an10classicalnicospecs.jpg
I think you'll be fine although it's really dependant on your enclosures. I have a 400 square foot apartment with 96db speakers and 4W is too loud. Energy RC-70. Have to shout over it. It's surprising just how much power 1 watt really is.
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My enclosure will be BassReflex about 189L, VAS = 124,6L
Seems Energy RC-70 is 92dB sensitivity (?)
http://www.soundandvision.com/conte...-rc-70-surround-speaker-system-specifications
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I've read 92 as well, but I've also seen 96 published. I would rate them 96 based on comparisons to other speakers though.
I'm sure 6-8W will be plenty.
What genre of music? I listen to a variety from jazz to drum and bass, jungle, and other bass heavy synthetic music. Some of which the bass line is pure sine. 4W is great. 16W is greater. My 16W is 4 6P3S push pull parallel per channel at B+ 460. My 4W is 410V push pull CCS loaded 6P3S. All triode connected and switchable to "high power". 16W has UL for 50W, 4W has screen regulated tetrode for 30W.
For the record my Apt Holman amp 1 I can't distort the output (120W) I just cant stand the SPL it creates!
OK, according this factory paper its 95dB for two speakers:
2 speakers in a typical room: 95 dB
http://www.energy-speakers.com/docs/common/RC-70/RC-70_OM.pdf
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So if 4W are plenty to your 92dB speaker, 10W will suit my FR.
I listen Jazz, Vocal Jazz, Classical, Prog Rock and Ambient among other styles.
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