just curious, which value capacitors did you use before, Terry ?
Beyschlag = Beyschlag Components =BC = Vishay BC
Beyschlag = Beyschlag Components =BC = Vishay BC
Actually, what happened is, the search engine for the electronics suppy wouldn't except pf for a value so I entered 00033uf thinking I needed 330pf. I hadn't noticed that it said 33-330pf in the BOM. If I had, I would have asked which value would be best before I ordered. Well anyway, when the matches popped up, it included 0.0033 as one of the choices. I selected the wrong part. I need to be more careful. That has happened to me before.
School of hard knocks I think it's called. It's a wonder I can still think with all these lumps on my head. 😀
Blessings, Terry
School of hard knocks I think it's called. It's a wonder I can still think with all these lumps on my head. 😀
Blessings, Terry
No pain, No gain, Terry.
I've been calculating with very large or very small numbers for a long time, and still it is easy to make a mistake.
Did it occur to you that this is the first time you traced an error completely on your own ? Seems you have working lumps.
I can imagine that the difference in capacitor values legitimates the transfer from the garage, poor old Hafler.
I've been calculating with very large or very small numbers for a long time, and still it is easy to make a mistake.
Did it occur to you that this is the first time you traced an error completely on your own ? Seems you have working lumps.
I can imagine that the difference in capacitor values legitimates the transfer from the garage, poor old Hafler.
Hi jacco,
Yes, there is no doubt that I am learning from all of these mistakes. Each time I get a little better grasp on what is going on.
The amp does sound better now, for sure. Don't feel too bad for the old Hafler. It has been in the shed up until now. At least it's filter caps are getting a charge now instead of drying out and growing old. 😀
I've got some questions about the Al's boards. I have been thinking of building a KSA100 with them instead of another KSA50. After reading back through some of the posts I get the feeling that the KSA100 doesn't sound as good as the KSA50.
1) Is this true?
2) If I go with the KSA 100 and dual transformers, what would be the best rating for the transformers? What did the original use?
3) Does the KSA 100 use more output transistors than the KSA 50?
4) I have the output boards left over from my KSA 50 since I used TO3's. If I need more outputs, will these boards work along with Al's boards?
If these questions have been asked, please forgive me. I really did try to search back through the thread for the answers.
Blessings, Terry
Yes, there is no doubt that I am learning from all of these mistakes. Each time I get a little better grasp on what is going on.
The amp does sound better now, for sure. Don't feel too bad for the old Hafler. It has been in the shed up until now. At least it's filter caps are getting a charge now instead of drying out and growing old. 😀
I've got some questions about the Al's boards. I have been thinking of building a KSA100 with them instead of another KSA50. After reading back through some of the posts I get the feeling that the KSA100 doesn't sound as good as the KSA50.
1) Is this true?
2) If I go with the KSA 100 and dual transformers, what would be the best rating for the transformers? What did the original use?
3) Does the KSA 100 use more output transistors than the KSA 50?
4) I have the output boards left over from my KSA 50 since I used TO3's. If I need more outputs, will these boards work along with Al's boards?
If these questions have been asked, please forgive me. I really did try to search back through the thread for the answers.
Blessings, Terry
1) Is this true?
> I've never listened to one but generally lower powered amps tend to sound better
2) If I go with the KSA 100 and dual transformers, what would be the best rating for the transformers? What did the original use?
>If I were build one it would hant 1kva trannies in it.
3) Does the KSA 100 use more output transistors than the KSA
50?
>Yes! 8 per channel in the original version.
4) I have the output boards left over from my KSA 50 since I used TO3's. If I need more outputs, will these boards work along with Al's boards?
>They should work fine but the way you hard wired it on the air tunel is better.
Mark
> I've never listened to one but generally lower powered amps tend to sound better
2) If I go with the KSA 100 and dual transformers, what would be the best rating for the transformers? What did the original use?
>If I were build one it would hant 1kva trannies in it.
3) Does the KSA 100 use more output transistors than the KSA
50?
>Yes! 8 per channel in the original version.
4) I have the output boards left over from my KSA 50 since I used TO3's. If I need more outputs, will these boards work along with Al's boards?
>They should work fine but the way you hard wired it on the air tunel is better.
Mark
Heard both the KSA50 as the 100 in the late 1980s, both MKIIs.
My choice of the two would be the KSA50, combined with big juice spenders a KSA100 might have more authority.
So it depends on the loudspeaker unit, i loathe Apogee's anyway.
The KSA100MKII did something like 160 watts in 8 ohm continuous, as far as i can recollect the toroids were in the order of 700W per channel.
(seemed to be a popular number in those years, Threshold used lots of toroids in the same class. Never managed to find out if Krell also used H&F produced toroids in those days, like Threshold and ML.)
My choice of the two would be the KSA50, combined with big juice spenders a KSA100 might have more authority.
So it depends on the loudspeaker unit, i loathe Apogee's anyway.
The KSA100MKII did something like 160 watts in 8 ohm continuous, as far as i can recollect the toroids were in the order of 700W per channel.
(seemed to be a popular number in those years, Threshold used lots of toroids in the same class. Never managed to find out if Krell also used H&F produced toroids in those days, like Threshold and ML.)
Terry,
One other thing you'd have to do to build it into a KSA-100 would be to install Stewart Easson's current source in place of the Zeners... or at least increase the resistirs in series with the zeners to limit the current to managable levels.
The diagrams of the MK-2 KSA-100 are not applicable to this board because of the multiple driver devices. Use one of the older KSA-100 diagrams and that should work ok.
Glad to hear the KSA-50 mystery is solved!!
Mark
One other thing you'd have to do to build it into a KSA-100 would be to install Stewart Easson's current source in place of the Zeners... or at least increase the resistirs in series with the zeners to limit the current to managable levels.
The diagrams of the MK-2 KSA-100 are not applicable to this board because of the multiple driver devices. Use one of the older KSA-100 diagrams and that should work ok.
Glad to hear the KSA-50 mystery is solved!!
Mark
Neychi, thanks for posting the pdf, nice to know what Krell used and when.
Funny that Krell did not use that voltage regulator circuit for the 50 and 100.
Funny that Krell did not use that voltage regulator circuit for the 50 and 100.
Looks like Mr d'Agostino had a fonding for Roederstein's too.
The goldies are EL/EB/EG series Roe capacitors.
The goldies are EL/EB/EG series Roe capacitors.
If anyone can see a single low quality component in the KMA100 you posted, i'm impressed.
imo, the big 4 US brands set the standard in the 80s for solid state build quality.
One that all others have been copying for the last 25 years.
Overhere, those were the best, obtainable, 105C capacitors, unless paying 3 times as much for Valvo RMR or Siemens Sikorel's low esl/esr for fast switching purposes.
I am about to use the last ones i've got for a set of front end voltage regulators.
The number of parallel capacitors on that KMA100 picture is a sight for sore eyes.
imo, the big 4 US brands set the standard in the 80s for solid state build quality.
One that all others have been copying for the last 25 years.
Overhere, those were the best, obtainable, 105C capacitors, unless paying 3 times as much for Valvo RMR or Siemens Sikorel's low esl/esr for fast switching purposes.
I am about to use the last ones i've got for a set of front end voltage regulators.
The number of parallel capacitors on that KMA100 picture is a sight for sore eyes.
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