Good idea on the LM-783 Brian!
I also did some harmonic distortion measurements. I was surprised at how high the distortion was. Came in @ 62% at 2 volts at 1khz. The manual just says less then 1%. It appears to be even order harmonic which is the least objectionable and the least noticeable to the ears. I wonder if we could up the current a bit like we do with Aleph amplifiers to lower it even further, the devices are pretty beefy? At least those of us who have heatsinked the devices would be able to...
I discovered a new high end coupling cap today.... A bit too pricy to use here though. http://www.lefson.com/cmod.php
Mark
I also did some harmonic distortion measurements. I was surprised at how high the distortion was. Came in @ 62% at 2 volts at 1khz. The manual just says less then 1%. It appears to be even order harmonic which is the least objectionable and the least noticeable to the ears. I wonder if we could up the current a bit like we do with Aleph amplifiers to lower it even further, the devices are pretty beefy? At least those of us who have heatsinked the devices would be able to...
I discovered a new high end coupling cap today.... A bit too pricy to use here though. http://www.lefson.com/cmod.php
Mark
TL783 will mess with your brain
being there , with Anzai preamp , few decades ago
finished with proper shunt tube supply
regarding Iq , give actual schematic and say what you need/want .......
being there , with Anzai preamp , few decades ago
finished with proper shunt tube supply
regarding Iq , give actual schematic and say what you need/want .......
Looks like any other three terminal, easy to use VR. What was your beef with it Zen? Other people seem to be using it in projects.
Mark
Mark
I also did some harmonic distortion measurements. I was surprised at how high the distortion was. Came in @ 62% at 2 volts at 1khz. The manual just says less then 1%.
Something's wrong. Are the fets biasing up nicely?
I wonder if we could up the current a bit like we do with Aleph amplifiers to lower it even further, the devices are pretty beefy?
Yes.
Good thing it's even order 😀 If it were odd order, something like 33% is total clipping. Total square waves with a sine wave input! Like a Jimi Hendrix guitar preamp! I have no idea what 62%THD would sound like 😀... I was surprised at how high the distortion was. Came in @ 62% at 2 volts at 1khz. The manual just says less then 1%. It appears to be even order harmonic which is the least objectionable and the least noticeable to the ears...Mark
I have used the LM783 in a tube amp bias supply before with good results. I needed -60volts for a KT88 PP amp and it did the trick. The zener stack in the P is just a voltage reference. The regulator is still a series pass regulator. When run balanced the P should present an easy load for a power supply, with a pretty much constant current requirement.
I'm surprised at those distortion measurements. Is that a typo. Perhaps.63 percent?
I'm surprised at those distortion measurements. Is that a typo. Perhaps.63 percent?
well , tube amp bias ( or any other sort of bias) supply is completely different issue
regarding distortion measurement - there was something fishy , no doubt 😉
regarding distortion measurement - there was something fishy , no doubt 😉
I think that 58v to 62v is fine . mine is at 59v when cold and 59.7 when hot.
Not totaly finished yet. Xlr not mounted.
it sound wonderful
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Not totaly finished yet. Xlr not mounted.
it sound wonderful
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the P1.7 is a supreme pre amp. i fell in love with mine 6 years ago. and it's still with me in daily use. and it will forever be 🙂
It's nice to see all the various builds. Clarity capacitors for output coupling! They are certainly very good in crossovers. How do you like them in this application?
lalaina,
Who's fader is that? I never seen that type before.... And nice job but consider using it in balanced mode!! Makes huge difference.
Mark
Who's fader is that? I never seen that type before.... And nice job but consider using it in balanced mode!! Makes huge difference.
Mark
Zen Mod,
I was using Gas Regulators on my 12B4 project and also outboard regulated variable supplies for B+ and filament. It sounds great to this day, I should make a balanced version!
Mark
I was using Gas Regulators on my 12B4 project and also outboard regulated variable supplies for B+ and filament. It sounds great to this day, I should make a balanced version!
Mark
It's nice to see all the various builds. Clarity capacitors for output coupling! They are certainly very good in crossovers. How do you like them in this application?
Yes , I'm realy happy with them.
3 years ago , I have upgraded the crossover of my JBL LS80 with the PX and the SA version. The sound is little warm and dark but detailled....
Now, I use the ESA version for the aleph p .I'm very happy with them.
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lalaina,
Who's fader is that? I never seen that type before.... And nice job but consider using it in balanced mode!! Makes huge difference.
Mark
Khozmo shunt attenuator, I use 5k ohm for the output.
High Quality Audio & Industrial Attenuators and Passive Preamplifiers
Yes, I will try the balanced config with my future aleph 60 mono block (a dream 🙂 ). For now, I use it with my f5t , not totally finished yet
still no more examples of new AlephP builds??
and I thought I was slow 🙂. as always the housing metal work plus packaging other equipment like a miniDsp and Damps is holding back my timeline. otherwise the four APv17 modules have been ready for a while now, all set at 18dB bal gain.
I will post when ready.
and I thought I was slow 🙂. as always the housing metal work plus packaging other equipment like a miniDsp and Damps is holding back my timeline. otherwise the four APv17 modules have been ready for a while now, all set at 18dB bal gain.
I will post when ready.
It's nice to see all the various builds. Clarity capacitors for output coupling! They are certainly very good in crossovers. How do you like them in this application?
I've used Clarity Caps as a parafeed capacitor in a few of my tube amps and have been very impressed with them
Debra
another CAP question....
Hi there,
I've built a zen-line stage with the original recommended film capacitors, years ago. She plays fine.
Now i wan't to make a step into building a P1.7, with the "veteran" boards.
Collecting the parts is not an issue, except the 10µF capacitors that fit the board....
I started looking for caps that match the lead spacing of 27,5mm. This results in only a few hits, mostly MKT.
Some MKP's were found, but they are unknown to me. Would any MKP be good enough/better than the original film caps ?
(i've found TDK, Visay types that would fit on the board)
BR,
Nick
Hi there,
I've built a zen-line stage with the original recommended film capacitors, years ago. She plays fine.
Now i wan't to make a step into building a P1.7, with the "veteran" boards.
Collecting the parts is not an issue, except the 10µF capacitors that fit the board....
I started looking for caps that match the lead spacing of 27,5mm. This results in only a few hits, mostly MKT.
Some MKP's were found, but they are unknown to me. Would any MKP be good enough/better than the original film caps ?
(i've found TDK, Visay types that would fit on the board)
BR,
Nick
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