Re: Absolutely
Good that's what I thought. I just had another member who made payment for 2 of these, backed off after reading your comments. I made him the refund, but wanted to set the record straight...
One of these would be ok for a KSA-50 and two would be absolutely no problems.
Thanks!
Stuart Easson said:
Good that's what I thought. I just had another member who made payment for 2 of these, backed off after reading your comments. I made him the refund, but wanted to set the record straight...
One of these would be ok for a KSA-50 and two would be absolutely no problems.
Thanks!
Hi All-
Update on the progress.
Last week Jan and the manufacturer worked out some lingering details and the boards are now in production.
They have a 2 week turn around time, and I will get them shipped out again as soon as possible once I receive them.
I will continue to update the thread as I get news.
Thanks again Jan for going WAY beyond designing and working with the manufacturer also!
Update on the progress.
Last week Jan and the manufacturer worked out some lingering details and the boards are now in production.
They have a 2 week turn around time, and I will get them shipped out again as soon as possible once I receive them.
I will continue to update the thread as I get news.
Thanks again Jan for going WAY beyond designing and working with the manufacturer also!
I guess I'll have to make my own boards. I'm too late to see this thread.
I do have 1ohm loads standing in my living room. Yes, they are the speakers that made KSA famous. I bought them for less than 700USD with one dead sub, restored them with less than 60USD, and here they are. With brand new finishing and singing the way they should, but I'm still not satisfied. I want a MONSTER amp. A low voltage monster. And I think KSA50 is my perfect choice.
Has anyone ever considered using Sanken A1216/C2922 for output stage? It's only $4 per piece here in my place (almost the same price as MOTO 15003)
I do have 1ohm loads standing in my living room. Yes, they are the speakers that made KSA famous. I bought them for less than 700USD with one dead sub, restored them with less than 60USD, and here they are. With brand new finishing and singing the way they should, but I'm still not satisfied. I want a MONSTER amp. A low voltage monster. And I think KSA50 is my perfect choice.
Has anyone ever considered using Sanken A1216/C2922 for output stage? It's only $4 per piece here in my place (almost the same price as MOTO 15003)
Hi All-
The boards are shipping to me today.
I should receive the PCB's from the factory on Wednesday or Thursday.
I will be repacking and shipping out to this weekend and Monday.
🙂
The boards are shipping to me today.
I should receive the PCB's from the factory on Wednesday or Thursday.
I will be repacking and shipping out to this weekend and Monday.
🙂
2sa1216
EJ, the sankens are fine transistors, I have a few, I can try them as the output stage once the boards get here and let you know. The only possible issue I can theorize is that the amp is designed to use relatively slow outputs, the sankens are much faster, and may need compensation the originals did not require.
Troy, awesome, perfect timing, I'm just finishing an aleph 50, soon be time for some back to back comparisons...
Stuart
EJ, the sankens are fine transistors, I have a few, I can try them as the output stage once the boards get here and let you know. The only possible issue I can theorize is that the amp is designed to use relatively slow outputs, the sankens are much faster, and may need compensation the originals did not require.
Troy, awesome, perfect timing, I'm just finishing an aleph 50, soon be time for some back to back comparisons...
Stuart
The part list recommend the MJL21193/94 with drivers MJE15032/33.
I can get at a good price the MJL21195/96 with drivers MJE15034/35.
Are these other parts number compatible with this desing?
From the specs, the only real difference seems to be that the 93/94 are rated at 2.25Amp SOA and the 85/96 are rated at 3A
The drivers 32/33 are rated 250V/8A, the 34/35 are 350V/4A!
Some that HV parts have a "glare" sound, so I guest the 32/33 is a better match.
Let me know your comments
I can get at a good price the MJL21195/96 with drivers MJE15034/35.
Are these other parts number compatible with this desing?
From the specs, the only real difference seems to be that the 93/94 are rated at 2.25Amp SOA and the 85/96 are rated at 3A
The drivers 32/33 are rated 250V/8A, the 34/35 are 350V/4A!
Some that HV parts have a "glare" sound, so I guest the 32/33 is a better match.
Let me know your comments
Anyone build the Krell clone yet?
Too late to buy boards I guess.
Also strongly considerly the Leach V4.5 amp.
Will the Krell work in class AB til proper transformer can be bought?
Tom
Too late to buy boards I guess.
Also strongly considerly the Leach V4.5 amp.
Will the Krell work in class AB til proper transformer can be bought?
Tom
tmblack said:
No one i know of yet, no boards!!!
I'm still waiting on cap's and toroids and casing!
It will work ok in class a/b, just lower the amount of bias used... you can still have class a for the first watt or two... What transformer do you have to use for it?
Aaron
[edit - i think a lot of people bought spare boards, so there may be some for later? depends if they want to sell!]
NUTTTR said:
Hi-
The GB of boards will hopefully arrive Wednesday or Thursday. I hope to get them out on Saturday or Monday.
Has anyone gathered the parts necessary (except boards of course) to complete theirs?
And please post pictures of the completed amps here when finished.
got parts?
ooo, me, me, I have...
I decided a while ago to make at least a couple of channels of all the 'classic' amps, been collecting parts ever since, hence the 'sculpture'. I recently traded for heatsinks and finally bought a stack of toroids from parts express, they are approx. 500va, and delivered, ended up costing $12 each, so I bought 10. I had to rewind one for the aleph, the default secondaries of 40-20-0-20-40 weren't cutting it, now it's 30-0, 30-0...much better.
So far I've built an aleph50, next will be the ksa50, then perhaps a quad 405, not sure after that, maybe a naim nap250...
So far the aleph50 has cost me ~$75, everything included, though it's not finished mechanically...might have to buy some metal extrusions to complete the case.
Stuart
ooo, me, me, I have...
I decided a while ago to make at least a couple of channels of all the 'classic' amps, been collecting parts ever since, hence the 'sculpture'. I recently traded for heatsinks and finally bought a stack of toroids from parts express, they are approx. 500va, and delivered, ended up costing $12 each, so I bought 10. I had to rewind one for the aleph, the default secondaries of 40-20-0-20-40 weren't cutting it, now it's 30-0, 30-0...much better.
So far I've built an aleph50, next will be the ksa50, then perhaps a quad 405, not sure after that, maybe a naim nap250...
So far the aleph50 has cost me ~$75, everything included, though it's not finished mechanically...might have to buy some metal extrusions to complete the case.
Stuart
Stuart-
Don't lose your camera again under that pile and take a few pictures if you don't mind.
I am curious to see which one you end up preferring.
Don't lose your camera again under that pile and take a few pictures if you don't mind.
I am curious to see which one you end up preferring.
pi filters
In case anyone was unsure just how good a pi filter can be...
For each polarity I built the PSU filter using a 2.7mh iron core, 16gauge choke between a pair of 68000uF caps, the ripple at 6amps is less than 10mv, DC voltage loss from the choke is about a volt...
Duncans psu simulator is absolutely great in this regard, every voltage and current I could check was as close as the tolerance of the components would allow, it's a great piece of software.
Stuart
In case anyone was unsure just how good a pi filter can be...
For each polarity I built the PSU filter using a 2.7mh iron core, 16gauge choke between a pair of 68000uF caps, the ripple at 6amps is less than 10mv, DC voltage loss from the choke is about a volt...
Duncans psu simulator is absolutely great in this regard, every voltage and current I could check was as close as the tolerance of the components would allow, it's a great piece of software.
Stuart
whats an aleph50
Ah, yes, good question...it's an aleph that puts out 50w per channel into 8 and 100w into 4. It is also the largest stereo aleph I can build using the heatsinks I have. It idles at about 300w, and uses 4 heatsinks as the sides of the cuboid case, and runs about 32c above ambient. I shamelessly copied the 'borg' look passlabs used.
Stuart
Ah, yes, good question...it's an aleph that puts out 50w per channel into 8 and 100w into 4. It is also the largest stereo aleph I can build using the heatsinks I have. It idles at about 300w, and uses 4 heatsinks as the sides of the cuboid case, and runs about 32c above ambient. I shamelessly copied the 'borg' look passlabs used.
Stuart
Re: pi filters
What size x-former did you use, and did you have any problems with inrush current?
I am planning a similar supply but 20,000uF first, coil, then 30,000uF for each channel x 3... I will use a single 1kV -1.2kV toroid but am concerned about inrush current from the 60kuF caps before the coils.
Any comments welcome.
Stuart Easson said:
What size x-former did you use, and did you have any problems with inrush current?
I am planning a similar supply but 20,000uF first, coil, then 30,000uF for each channel x 3... I will use a single 1kV -1.2kV toroid but am concerned about inrush current from the 60kuF caps before the coils.
Any comments welcome.
inrush current...
I was worried about it at first, but after simulating, then building it wasn't a problem. The toroid I'm using is ~500va, smaller than yours, but the caps are larger. When I plug the transformer into the power, the lights blink, but they do that whether the caps are attached or not...I've read it's the core having to achieve a certain flux density before the emf from the transformer can inhibit the incoming current.
Originally I was going to use a pair of the transformers, but thus far a single seems to be able to do the trick, after it was rewound to get more current and less voltage.
Stuart
I was worried about it at first, but after simulating, then building it wasn't a problem. The toroid I'm using is ~500va, smaller than yours, but the caps are larger. When I plug the transformer into the power, the lights blink, but they do that whether the caps are attached or not...I've read it's the core having to achieve a certain flux density before the emf from the transformer can inhibit the incoming current.
Originally I was going to use a pair of the transformers, but thus far a single seems to be able to do the trick, after it was rewound to get more current and less voltage.
Stuart