koldby said:
I was born in Frederiksberg, grew up around Bronshoj-Husum-Gladsaxe area. Still got a Danish Passport, 'nuf said? My sister lives near Helsingor (Elsinore in English, thanks to Shakespeare who seemed to take a liking to the castle). My kid brother lives in Norway - a place called Kongsvinger. But I have more hair than he does, must be the freezing temperatures? You know that big hospital in Copenhagen (Kobenhavn), I think it's called Rigshospitalet or somesuch. My great-great-great-grandfather was the founder. I believe there is a statue of him somethere on the grounds. Do me a favour? Find it and take a pic, then email it to me?
Anything else you wanna know?
Joe R.
Hi Joe
I know Rigshospitalet, actually my wife was educated there, and when I get the oppertunity , I will try to find the statue and get a picture of it. Can't tell you when as I am not living in København.
Hilsen
Koldby
I know Rigshospitalet, actually my wife was educated there, and when I get the oppertunity , I will try to find the statue and get a picture of it. Can't tell you when as I am not living in København.
Hilsen
Koldby
My latest boards:
of course, they will include a t-network for feedback, but the boards don't reflect this 😀
Franz
An externally hosted image should be here but it was not working when we last tested it.
of course, they will include a t-network for feedback, but the boards don't reflect this 😀
Franz
No, I dont work, at least not for salary
!So easy!
But I wish to work with audio (and earn some money). More and more. And I work on it!
Franz
BTW:
Do you know Esquivel? Space Age sound out of the end of the fifties? Playing with stereo effects?
Yes, it is an ECC88. I just plugged it in, but I would use the same values as with an E88CC:
10K Rk.
Franz
10K Rk.
Franz
Yes, in German Kathodenfolger, imho. The power stage is coupled at the cathode. Maybe the wrong terminology?
This is the tube buffer version. Unity gain at the tube stage.
I am not convinced from my other trials with the voltage gain tube stage and the "unity gain" LM3875 powerstage.
This project is cancelled for me. A tube amp is a tube amp, and I definitefly love them. But with true tube power stage and output transformer (or OTL).
But for gainclones, easy and good sounding solutions, need a high gain of the LM chip (not too much feedback) and in the inverting topology a very good buffer (for impedance matching, buffering).
Could be an OPA627 or maybe better a tube/valve?
It is really not the case, that the valve just adds harmonic distortion, this is not the case in this circuit. The tube in this configuration is a perfect (audio) buffer: very fast and accurate, class-A...
Franz
This is the tube buffer version. Unity gain at the tube stage.
I am not convinced from my other trials with the voltage gain tube stage and the "unity gain" LM3875 powerstage.
This project is cancelled for me. A tube amp is a tube amp, and I definitefly love them. But with true tube power stage and output transformer (or OTL).
But for gainclones, easy and good sounding solutions, need a high gain of the LM chip (not too much feedback) and in the inverting topology a very good buffer (for impedance matching, buffering).
Could be an OPA627 or maybe better a tube/valve?
It is really not the case, that the valve just adds harmonic distortion, this is not the case in this circuit. The tube in this configuration is a perfect (audio) buffer: very fast and accurate, class-A...
Franz
Yes, exactly this man!
Absolutely amazing, you should listen to this music. He rented three studios, one for the right channel, one for the left channel and one for the virtual center.
And the musicians where "networked" by headphones. And he played with the stereo effects.
End of the 50ties, beginning of the 60ies! Came from Mexico City to New York to break the rules and makes good business, good sound and plays with the actual technology.
Secret tip...
Franz
P.S.
I will measure the grid bias tomorrow. The grid is at ground level, the bias must be around -4V, I think.
Absolutely amazing, you should listen to this music. He rented three studios, one for the right channel, one for the left channel and one for the virtual center.
And the musicians where "networked" by headphones. And he played with the stereo effects.
End of the 50ties, beginning of the 60ies! Came from Mexico City to New York to break the rules and makes good business, good sound and plays with the actual technology.
Secret tip...
Franz
P.S.
I will measure the grid bias tomorrow. The grid is at ground level, the bias must be around -4V, I think.
Please allow me:
this is my prefered Esquivel album:
http://www.amazon.com/exec/obidos/t...104-2587794-0283927?v=glance&s=music&n=507846
I post this, because here, you can listen to samples (Mucha muchacha, Sentimental Journey...)
Franz
this is my prefered Esquivel album:
http://www.amazon.com/exec/obidos/t...104-2587794-0283927?v=glance&s=music&n=507846
I post this, because here, you can listen to samples (Mucha muchacha, Sentimental Journey...)
Franz
After adding a regulated PSU to my VBIGC, I cannot close the box anymore:
A real mess In this setup, it is completely impossible to change something at the amp-boards, without removing them and then puzzling again back in the box, put glimmer plates in place etc... 
I am happy about the sound quality, but I could not live with THIS amp!
Thats why, I made a new board including everything. And I ordered a new chassis, coming within the next two weeks.
Franz
An externally hosted image should be here but it was not working when we last tested it.
A real mess
In this setup, it is completely impossible to change something at the amp-boards, without removing them and then puzzling again back in the box, put glimmer plates in place etc... I am happy about the sound quality, but I could not live with THIS amp!
Thats why, I made a new board including everything. And I ordered a new chassis, coming within the next two weeks.
Franz
Franz, may I suggest that you change those speaker cables for some made from solid core Cat5? I use two pairs per channel and it is a big improvement over the stranded cables that I have similar to the ones in your picture. 😉
Something for you to try while you wait for your new PCB/chassis to arrive!
Something for you to try while you wait for your new PCB/chassis to arrive!
Nuuk said:Franz, may I suggest that you change those speaker cables for some made from solid core Cat5? I use two pairs per channel and it is a big improvement over the stranded cables that I have similar to the ones in your picture. 😉
Something for you to try while you wait for your new PCB/chassis to arrive!
Great suggestion, Nuuk! A zobel might be in order though.
Carlos
Hi,
And another one:
Remove the screening can from the buffer and see if you hear a difference.
As it is a cathode follower, chances are there won't be much difference but still worth a try.
If a single ECC88 is used for both channels, channel separation can be markedly improved by grounding pin #9 (the internal shield) at the expense of a small increase of interelectrode capacitance.
Cheers,😉
And another one:
Remove the screening can from the buffer and see if you hear a difference.
As it is a cathode follower, chances are there won't be much difference but still worth a try.
If a single ECC88 is used for both channels, channel separation can be markedly improved by grounding pin #9 (the internal shield) at the expense of a small increase of interelectrode capacitance.
Cheers,😉
Franz G said:
Franz, with some arrangements I think that everything should fit in that box.
Put the tube in a vertical position and make a round hole on the top of the case.😱
People like to see tubes glowing.😀
You will also get some space from doing this.
The board that has the 10,000uf/50v caps could be mounted on the other way around. The caps won't fit, but make two big round holes on the top of the case.😱
I wouldn't mind to see those caps, they seam like Jamicon and they are not ugly.😀
Three holes on the case?
Hey Guys!
No, not anymore, as there is really no difference with my setup. I prefer to completely avoid any passive parts and just have short cables.
For what? I tried zobel, LR and everything. But there is no problem without it, in my setups!
Of course, I used it with and without the screening can. No difference!
Of course, pin 9 is grounded. 🙂
This amp is already history 😀
Something like this: http://www.audiodiskussion.de/foren/marktplatz/msg.php?idx=554 (still for sale).
Franz
No, not anymore, as there is really no difference with my setup. I prefer to completely avoid any passive parts and just have short cables.
For what? I tried zobel, LR and everything. But there is no problem without it, in my setups!
Of course, I used it with and without the screening can. No difference!
Of course, pin 9 is grounded. 🙂
This amp is already history 😀
Something like this: http://www.audiodiskussion.de/foren/marktplatz/msg.php?idx=554 (still for sale).
Franz
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