What transformers are you going to use for the PCBs(both)?
IIRC you said to try and avoid toroidals but was that only for the KSA clone?
EDIT: Oh and the PCB's look GREAT!! I am fighting the urge to start another project...
What transformers are you going to use for the PCBs(both)?
I will use the EI transformer.
IIRC you said to try and avoid toroidals but was that only for the KSA clone?
Yes!
EDIT: Oh and the PCB's look GREAT!! I am fighting the urge to start another project
Thanks！Your project? May share?
I will use the EI transformer.
IIRC you said to try and avoid toroidals but was that only for the KSA clone?
Yes!
EDIT: Oh and the PCB's look GREAT!! I am fighting the urge to start another project
Thanks！Your project? May share?
After 8 times read 8000 post i found that
original supply was 40.000 uf per channel
pls look algar_emi question there
http://www.diyaudio.com/forums/solid-state/31077-krell-ksa-50-pcb-54.html
too much supply will give you influence
a little or a lot, i think 48.000 uf for me is enough
gxcnabin i wanna ask your opinion
what is different between use 2 pair or 4 pair output device
per channel, will it help for the hot condition ?
original supply was 40.000 uf per channel
pls look algar_emi question there
http://www.diyaudio.com/forums/solid-state/31077-krell-ksa-50-pcb-54.html
too much supply will give you influence
a little or a lot, i think 48.000 uf for me is enough
gxcnabin i wanna ask your opinion
what is different between use 2 pair or 4 pair output device
per channel, will it help for the hot condition ?
I am fighting the urge to start this.. I already have multiple amp projects in the works and can't justify another even though there has always been a soft spot in my heart for the Krell KSA-50.
OK , so this board is based on the ksa 50 and not the ksa50 mk2
Here is my question. Did the ksa 50 also run on +-45V or was it toned down to around +-36v or +-38V
I can't much info on the ksa 50 but much on the ks50 mk2.
Do I even have these facts straight?
Here is my question. Did the ksa 50 also run on +-45V or was it toned down to around +-36v or +-38V
I can't much info on the ksa 50 but much on the ks50 mk2.
Do I even have these facts straight?
Hi there.
I am late to the party, but are there any free boards left please?
Many thanks,
- John
I am late to the party, but are there any free boards left please?
Many thanks,
- John
ok , ithink i found my answer here:
Chapter 2: References and Corrections - diyAudio
"In the original Krell it was ~37.5 VDC, bias ~1.9A per channel, ~60w/8ohm class A, ~75w/8ohm class AB
People have built these unmodified with 39VDC
Transformers:
Krell used a 400va transformer per channel, ie two per stereo chassis. In the course of production they used both
toroids and EI transformers so no big deal there.
A normal KSA50 channel has ~37v rails. This requires 2 secondaries at ~26v AC, or 52v center tapped. A minimal
transformer for two channels would be about 400va, you'd want more for driving low impedance loads. "
Chapter 2: References and Corrections - diyAudio
"In the original Krell it was ~37.5 VDC, bias ~1.9A per channel, ~60w/8ohm class A, ~75w/8ohm class AB
People have built these unmodified with 39VDC
Transformers:
Krell used a 400va transformer per channel, ie two per stereo chassis. In the course of production they used both
toroids and EI transformers so no big deal there.
A normal KSA50 channel has ~37v rails. This requires 2 secondaries at ~26v AC, or 52v center tapped. A minimal
transformer for two channels would be about 400va, you'd want more for driving low impedance loads. "
In case you are wondering about the 1.9A and 60W, the region just before a device switches off is non-linear.
Thus, a full 50W of crossover distortion free power requires a bit higher bias level than the number which corresponds to 50W.
1.9A bias results in a true Class A power level that's closer to 50 than to 60W.
Thus, a full 50W of crossover distortion free power requires a bit higher bias level than the number which corresponds to 50W.
1.9A bias results in a true Class A power level that's closer to 50 than to 60W.
very true.
In the Krell KSA50 case we have an extra 132mA of bias to ensure we have a clean 50W of ClassA output Power, equivalent to 3.535A of ClassA output current.
Thanks
At this stage I am not too worried about getting 50W exactly. I am guessing whichever heat sinks I find in the end will limit me. IT will be a process of switching it on at very low bias current and slowly turning up over a matter of a few hours while measuring the temp.
I was just curious about the effect that a 45V rails will have on the 2 pairs of devices on this design , compared to the 3 to 4 pairs used in other designs.
My power supply that i am going to test with is +-35V DC 40000uF per rail
(25V AC 500Va toroidal)anyway..
I'll decide from their if I can or even need to go higher.
At this stage I am not too worried about getting 50W exactly. I am guessing whichever heat sinks I find in the end will limit me. IT will be a process of switching it on at very low bias current and slowly turning up over a matter of a few hours while measuring the temp.
I was just curious about the effect that a 45V rails will have on the 2 pairs of devices on this design , compared to the 3 to 4 pairs used in other designs.
My power supply that i am going to test with is +-35V DC 40000uF per rail
(25V AC 500Va toroidal)anyway..
I'll decide from their if I can or even need to go higher.
Attachments
Now that is pretty... (amazing what things a geek like me finds to be beautiful)
Nahhh, it is absolutely beautiful, it's not a matter of personal taste. Every body SHOULD love it 😀
Thank you a lot Neychi for the input
4 x 20.000 uf 😱
Hip Hip Horeee ... Uncle Jacco Here
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