Transformers, CHEAP!
Hey guys, I found a GREAT deal on transformers for the KSA50 and KSA100 MKII projects.
There is a guy selling 1240va transformers with dual, center tapped, braided, 14AWG stranded secondaries at 30-0-30 each.
They are really nicely built with a potted center, flux band, and 18AWG braided, stranded primaries.
The really cool thing about these transformers is that they have dual 100v & 120v primaries for lots of different possibilities. If you use the 100v primaries with the typical 117v-120v input, you get 36.5-0-36.5 output.
I bought two of them to use with this project and after I received them I was so impressed with their build quality and versatility that I bought two more. I will post some pictures of them in a little bit.
The best part about them is the price. I talked to him about DIYAudio and he said he would sell them to anyone here that wanted them for $59 SHIPPED to your door!! In the US of course, but he seems like a nice guy and I'm sure will ship elsewhere also. He said he has ~50 of them left.
I am not associated with this guy and I don't know him other than I am a satisfied customer. This is just a heads up for anyone looking for nice transformers for these projects without breaking the bank.
His e-mail is dbslam@gmail.com. Tell him you are from DIYAudio.
Hey guys, I found a GREAT deal on transformers for the KSA50 and KSA100 MKII projects.
There is a guy selling 1240va transformers with dual, center tapped, braided, 14AWG stranded secondaries at 30-0-30 each.
They are really nicely built with a potted center, flux band, and 18AWG braided, stranded primaries.
The really cool thing about these transformers is that they have dual 100v & 120v primaries for lots of different possibilities. If you use the 100v primaries with the typical 117v-120v input, you get 36.5-0-36.5 output.
I bought two of them to use with this project and after I received them I was so impressed with their build quality and versatility that I bought two more. I will post some pictures of them in a little bit.
The best part about them is the price. I talked to him about DIYAudio and he said he would sell them to anyone here that wanted them for $59 SHIPPED to your door!! In the US of course, but he seems like a nice guy and I'm sure will ship elsewhere also. He said he has ~50 of them left.
I am not associated with this guy and I don't know him other than I am a satisfied customer. This is just a heads up for anyone looking for nice transformers for these projects without breaking the bank.
His e-mail is dbslam@gmail.com. Tell him you are from DIYAudio.
Hopefully this will help some of you out that were looking for transformers for this project.
You could also use the dual secondaries for +60 / -60 without the center taps. Then using the 100V primaries I measured 72.85VAC each. You could build a pretty beefy amp with that voltage for each rail. I come up with 103VDC for each rail in that configuration.
Let me know if any of you buy these. I would like to know what you think of them.
Thanks,
Donovan
You could also use the dual secondaries for +60 / -60 without the center taps. Then using the 100V primaries I measured 72.85VAC each. You could build a pretty beefy amp with that voltage for each rail. I come up with 103VDC for each rail in that configuration.
Let me know if any of you buy these. I would like to know what you think of them.
Thanks,
Donovan
I'm not sure what they are made from, or if you can add them to an existing transformer.
I know they are pretty standard in higher end torroids used for audio. I have seen them on the Plitrons, etc.
I think it helps to contain the magnetic flux, so you get less interference from the transformer.
I'm sure someone around here could explain it to us.
Thanks,
Donovan
I know they are pretty standard in higher end torroids used for audio. I have seen them on the Plitrons, etc.
I think it helps to contain the magnetic flux, so you get less interference from the transformer.
I'm sure someone around here could explain it to us.
Thanks,
Donovan
I modified my 1000VA transformers from 74-0+74-0 to 37-0 times four.
Initially I ran the secondaries in parallel but the rectifer got too hot to touch (no sink fitted).
I changed to dual rectifiers, with a single rectifier across each 37-0-37, then paralleled the outputs of the rectifiers.
Sharing the secondary current this way made the rectifiers run much cooler.
Initially I ran the secondaries in parallel but the rectifer got too hot to touch (no sink fitted).
I changed to dual rectifiers, with a single rectifier across each 37-0-37, then paralleled the outputs of the rectifiers.
Sharing the secondary current this way made the rectifiers run much cooler.
Transformer update
Here is the link to Scott's e-bay sale;
http://cgi.ebay.com/Toroid-TI-04322...oryZ4660QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Apparently the transformers I got were a little different than the models he has listed on e-bay and he is out of the model I bought now. The model on e-bay is very similar, it just has a bit different secondary voltages (~29.4-0-29.4 unloaded). They are perfect for what we are doing with them in this project.
Thanks,
Donovan
Here is the link to Scott's e-bay sale;
http://cgi.ebay.com/Toroid-TI-04322...oryZ4660QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
Apparently the transformers I got were a little different than the models he has listed on e-bay and he is out of the model I bought now. The model on e-bay is very similar, it just has a bit different secondary voltages (~29.4-0-29.4 unloaded). They are perfect for what we are doing with them in this project.
Thanks,
Donovan
Cerwin Vega a-2200 ?Mark. A. G.?
Hello everyone,
i stumbled across this wonderful forum when is was looking for information about a cerwin-vega a-2200 amp which i bought for a bargain on ebay germay
unfortunately i don't have any further information about this amp and i would be very thankful for any detail i can get !
Mark A. G. mentioned in some thread, that he got one of the same kind and is currently modifying it ?!
Thank you !
toby
Hello everyone,
i stumbled across this wonderful forum when is was looking for information about a cerwin-vega a-2200 amp which i bought for a bargain on ebay germay
unfortunately i don't have any further information about this amp and i would be very thankful for any detail i can get !
Mark A. G. mentioned in some thread, that he got one of the same kind and is currently modifying it ?!
Thank you !
toby
Attachments
Just got 2 of these. Great quality. They have a bel canto part number TT250 Rev E on them. KSA50 is underway, enclosure is only part to be obtained. Have some HUGE heatsinks, bigger than any Krell I have ever seen. 39 pounds per channel. Thinking of 4 pairs a1943\c5200 and 2 pinkmouse driver boards to minimize lead length. Hope Mark has a few more boards....I need 4 more for driver and output boards.
Bob G.
Bob G.
All of this seems to refer to a Krell KSA 50 Mk II . I am not sure what the exact differences are with these two. I own and use an original KSA 50 Mk I and this is the big heavy unit with full 50watt class A output and a fan that is noisy but very nessesary as the unit does run very hot when it is idling.
Mine has a small amount of work done ,change to schottky diodes , Kimber bypass caps, but is mostly as standard. Sound is very good indeed with great bass weight and very smooth powerful powerful sound without being too shrill and relentless as some solid state amps can be.
Is there a good schematic about for the KSA Mk i unit ?
Regards
Bencat
PS the big difference with KMA units is that they moved away form pure class A to what Krell describe as Plateaux Bias Class A. Probably a very clever circuit but not as purs as just the original Class A .
Mine has a small amount of work done ,change to schottky diodes , Kimber bypass caps, but is mostly as standard. Sound is very good indeed with great bass weight and very smooth powerful powerful sound without being too shrill and relentless as some solid state amps can be.
Is there a good schematic about for the KSA Mk i unit ?
Regards
Bencat
PS the big difference with KMA units is that they moved away form pure class A to what Krell describe as Plateaux Bias Class A. Probably a very clever circuit but not as purs as just the original Class A .
