G.Kleinschmidt said:
Yes.
Send GKlein images of all your finished K10A 🙂
Is there any new revision version you have updated with, GKlein?
If not, I guess you are very satisfied with this K10A.
Lineup regards
I'm still not finished - I haven't touched it since.
Too many other duties at this time of the year but I look forward to finishing my version in the fall, early winter.
Too many other duties at this time of the year but I look forward to finishing my version in the fall, early winter.
He he 🙂
Very strange, but I have the same stop in progress.
I'm sorry .. I was allmost finished when other things came up. I'm not surprised though. I have thousands of projects gong on an allmost every one get finished, but not at the same time.
I'll be back.😉
Very strange, but I have the same stop in progress.
I'm sorry .. I was allmost finished when other things came up. I'm not surprised though. I have thousands of projects gong on an allmost every one get finished, but not at the same time.
I'll be back.😉
lineup said:
Thanks Lineup.
I've considered laying out a version using 2SK/2SJ Lateral Mosfets for the output stage intead of the 2N3055/MJ2955 with a revised compensation scheme to make a very wide bandwidth version, but too many other thing to do on the list. I just got back from a 2 week geofiz field trip. Now I'm finishing off a spiffy audio spectrum analyzer for VGA/SVGA monitors.
Cheers,
Glen
Attachments
Good evening gentlemen (actually godnight here in Sweden 🙂 )
I just want to cheer Mr Kleinschmidt up and also the rest of the crew who bought cards from down under.
I'm up and running !
I have only measured DC levels and then done listening tests for more then an hour now.
This amplifier sounds good. Almost as good as my reference headphoneamp I built earlier this year. One major difference is a slight 100hZ buzz which I only hear without music or between tracks. Measured to 4mV p-p when paused CD player (scope) with the listening level quite high when played. (using two 15000uF in paralell for both channels)
Bias was adjusted to 350mv over both 0.22ohm resistors, after some warming up. After one more hour and listening trough headphones, the bias had dropped to 340mV.
HS. is 101VDC (27.5V~ primary)
Everything gets hot in this beauty 😀
I think the heatzinks should do though. After 1 1/2 hour I can touch the transistors for two seconds with the finger without taking it away (not more... ) Same to the big transformer. My transformer should do over 4 amps continuously its' stamped, but it really gets hot. Holding the heatzinks outside the amp is no problem. You can hold the hand on them. Even the heatzink on the 25A rectifier is a bit hot. I think this is normal for a Class A amp. Time will tell 😉 .
Next thing is the zobel network and play through speakers. Some measuring with sine generator and scope and also some pictures.
Eventually I will fit two EM84's when I have done a schematic and done some testing with it. After that I will order a nice gold eloxide aluminum front with milled slots for the EM84's and also the engraved text The Kleinschmidt 10A
I hope this can kick some *** on the other PCB card buyers.
Is there anyone more near a working unit?
I just want to cheer Mr Kleinschmidt up and also the rest of the crew who bought cards from down under.
I'm up and running !
I have only measured DC levels and then done listening tests for more then an hour now.
This amplifier sounds good. Almost as good as my reference headphoneamp I built earlier this year. One major difference is a slight 100hZ buzz which I only hear without music or between tracks. Measured to 4mV p-p when paused CD player (scope) with the listening level quite high when played. (using two 15000uF in paralell for both channels)
Bias was adjusted to 350mv over both 0.22ohm resistors, after some warming up. After one more hour and listening trough headphones, the bias had dropped to 340mV.
HS. is 101VDC (27.5V~ primary)
Everything gets hot in this beauty 😀
I think the heatzinks should do though. After 1 1/2 hour I can touch the transistors for two seconds with the finger without taking it away (not more... ) Same to the big transformer. My transformer should do over 4 amps continuously its' stamped, but it really gets hot. Holding the heatzinks outside the amp is no problem. You can hold the hand on them. Even the heatzink on the 25A rectifier is a bit hot. I think this is normal for a Class A amp. Time will tell 😉 .
Next thing is the zobel network and play through speakers. Some measuring with sine generator and scope and also some pictures.
Eventually I will fit two EM84's when I have done a schematic and done some testing with it. After that I will order a nice gold eloxide aluminum front with milled slots for the EM84's and also the engraved text The Kleinschmidt 10A
I hope this can kick some *** on the other PCB card buyers.
Is there anyone more near a working unit?
Fantastic! I'm glad you're pleased with it. 🙂
I have not tried listening to mine through headphones, but I suspect the faint buzz won't be there to bother you when you listen through speakers.
Cheers,
Glen
I have not tried listening to mine through headphones, but I suspect the faint buzz won't be there to bother you when you listen through speakers.
Cheers,
Glen
Stupid me still hasn't found proper type voltage bump-up transformers.
Only PCB mount types, larger VA than specified too, and they cost mullah.
I need 6 of them, i'll shag a steroid swallowing muscle beach babe before coughing up so much for whimpy transformers.
Got any pretty booby pics for a bald retard who has to do humiliating exercises all week because he dislocated a disc after falling down a staircase ?
Only PCB mount types, larger VA than specified too, and they cost mullah.
I need 6 of them, i'll shag a steroid swallowing muscle beach babe before coughing up so much for whimpy transformers.
Got any pretty booby pics for a bald retard who has to do humiliating exercises all week because he dislocated a disc after falling down a staircase ?
If he can post boobies, then I can post a pair of great tits... erm bits with a T
Come on, man, we want more reviews on the sound, I needed to delay my build a little to free up some cash for neccesities.
Jacco which transformers are we looking for?
Jon, I speak under correction, but most of the 12ax7s heater filaments are not visible... i.e. not very intreresting looking...
An externally hosted image should be here but it was not working when we last tested it.
Come on, man, we want more reviews on the sound, I needed to delay my build a little to free up some cash for neccesities.
Jacco which transformers are we looking for?
Jon, I speak under correction, but most of the 12ax7s heater filaments are not visible... i.e. not very intreresting looking...
Nordic said:
Single 30Vac or twin 15Vac secondaries, 5-15VA, (open) chassis mount types.
I can locate 5000VA toroids and other weird stuff, but unable to trace an easy source for these silly buggars.
Danni Aiello in Hudson Hawk : Can you f-believe it ? Gawd, i'm such a loser
(the Bit on the left looks like he ended up with a bandaged paw after attempting the tricky Kama Sutra hummingbird position. In car terms a bit of a Ford Pee-bird if you ask me. Yella is not really my thing anymore, i was married to one)
jacco vermeulen said:Got any pretty booby pics for a bald retard who has to do humiliating exercises all week because he dislocated a disc after falling down a staircase ?
I'm quite fond of these ones. Can't help with transformers in Holland though.
Cheers,
Glen
An externally hosted image should be here but it was not working when we last tested it.
Radioman62 said:Good evening gentlemen (actually godnight here in Sweden 🙂 )
I just want to cheer Mr Kleinschmidt up and also the rest of the crew who bought cards from down under.
I'm up and running !
I have only measured DC levels and then done listening tests for more then an hour now.
This amplifier sounds good. Almost as good as my reference headphoneamp I built earlier this year. One major difference is a slight 100hZ buzz which I only hear without music or between tracks. Measured to 4mV p-p when paused CD player (scope) with the listening level quite high when played. (using two 15000uF in paralell for both channels)
Bias was adjusted to 350mv over both 0.22ohm resistors, after some warming up. After one more hour and listening trough headphones, the bias had dropped to 340mV.
HS. is 101VDC (27.5V~ primary)
Everything gets hot in this beauty 😀
I think the heatzinks should do though. After 1 1/2 hour I can touch the transistors for two seconds with the finger without taking it away (not more... ) Same to the big transformer. My transformer should do over 4 amps continuously its' stamped, but it really gets hot. Holding the heatzinks outside the amp is no problem. You can hold the hand on them. Even the heatzink on the 25A rectifier is a bit hot. I think this is normal for a Class A amp. Time will tell 😉 .
Next thing is the zobel network and play through speakers. Some measuring with sine generator and scope and also some pictures.
Eventually I will fit two EM84's when I have done a schematic and done some testing with it. After that I will order a nice gold eloxide aluminum front with milled slots for the EM84's and also the engraved text The Kleinschmidt 10A
I hope this can kick some *** on the other PCB card buyers.
Is there anyone more near a working unit?
Hey lineup, err, groman err halojoy, what happened to your name???
Jan Didden
I'm also not sure what you mean Jan Didden 😕
I use to call myself Radioman or Radioman62 allaround the world where I join forums. Sometimes Radioman is occupied but I have never seen any "active" other Radioman so far 🙂
I understand that some people have several aliases and pretend to be different persons. I don't see the point. I have enough trouble to keep up with my one and only me
Regarding the amplifier in this thread .....
After some hours with new Electro Harmonix ECC83 tubes the amp started to drift on one channel and I wasn't able to bring the bias up to par with the working one. The amp clipped early on the negative side of the sinewave and almost no power when driven speakers. Changing to Sovtek ECC83LPS solved the problem. Maybe the low B+ is a bit challenging for certain tubes?
Further on I will test with some other old NOS tubes. Even my NOS ECC803S matched queens of triodes will be tested 😎
I use to call myself Radioman or Radioman62 allaround the world where I join forums. Sometimes Radioman is occupied but I have never seen any "active" other Radioman so far 🙂
I understand that some people have several aliases and pretend to be different persons. I don't see the point. I have enough trouble to keep up with my one and only me
Regarding the amplifier in this thread .....
After some hours with new Electro Harmonix ECC83 tubes the amp started to drift on one channel and I wasn't able to bring the bias up to par with the working one. The amp clipped early on the negative side of the sinewave and almost no power when driven speakers. Changing to Sovtek ECC83LPS solved the problem. Maybe the low B+ is a bit challenging for certain tubes?
Further on I will test with some other old NOS tubes. Even my NOS ECC803S matched queens of triodes will be tested 😎
Radioman62 said:
Hi Radioman.
The EH most likely draws excessive grid current, which does stuff up the biasing.
I have not tried an EH 12AX7 myself, but I have tested the amp with a variety of NOS 12AX7's of various brands (even a couple of used ones) and the bias current in all cases was negligible.
BTW, how is the amp working with the speakers connected?
Cheers,
Glen
I'll confirm the EH thing when I build up mine, I have 2 of those tubes waiting for installation. But if it was the tubes, shouldn't he have trouble on both channels....
Other times I had problems with a single class A channel from a set drifting, it turned out the two channels just didn't want to operate off the transformer I had, at the same time...
Other times I had problems with a single class A channel from a set drifting, it turned out the two channels just didn't want to operate off the transformer I had, at the same time...
- Status
- Not open for further replies.