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PostPosted: 05 Dec 2010, 21:20 
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IMO your budget dictates a SS power rectifier and capacitive filtering, so your next big ticket item will be the high voltage filter caps for the power supply.
Chokes don't need to be expensive and the addition of even a modest size choke can reduce ripply by over 20dBv vs RC filtering alone. The $10.95 RDC-100 8H choke from Radio Daze will fit into even modest amp budgets and still give excellent power supply results. If the amp is small (5W/channel SE) then one will do. If higher power, then split the supply after the primary filter cap and use one for each channel. Further more Antique Electronic Supply has 100µf/450VDC axial lead capacitors (search for C-ET100-450) for only $4.20 each and the JJ multi-section caps (I've had very good results with these) dual 100µf/500VDC for only $11.75 each.

I guess all that I'm saying is that a good power supply doesn't need to cost a fortune. :$: People often times over look good parts because they are not trendy. Just my :2c: worth.

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PostPosted: 05 Dec 2010, 21:38 
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I'm wondering if some commonly available transformers could be used as chokes for less than the cost of a "real" choke. I may measure the inductance of some of the isolation trannys I have laying around (up to 2.5 amps capacity, as low as 100mA). I find 120/120V or 120/240V isolation trannys are readily available and the surplus units are priced less than the cost of making them in many cases, which is why I like to use them in series for power, and even parallel. In the case of the 6C33C OTL I'll have a bank of five 100VA, 120V isolation transformers in parallel on each side of the split +/-150V supply for 1000VA of capacity.

I may try a couple of those 8H chokes on a smaller amp. I may need to split the load, but no problem there.

Good point with the caps. I'll add that the price of caps is all over the place. Look around, or use the recommended caps if they are suitable, or buy something similar that is what you need, and don't overspend.

Gather your ENTIRE parts list together before you order anything to try to minimize shipping costs and to determine what the amp will ACTUALLY cost you instead of what you THINK it will cost you.

And I have nothing against chokes. If the price is right go for it. :up:

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PostPosted: 05 Dec 2010, 23:10 
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Joined: 16 Nov 2010, 22:19
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Suncalc wrote:
Quote:
IMO your budget dictates a SS power rectifier and capacitive filtering, so your next big ticket item will be the high voltage filter caps for the power supply.
Chokes don't need to be expensive and the addition of even a modest size choke can reduce ripply by over 20dBv vs RC filtering alone. The $10.95 RDC-100 8H choke from Radio Daze will fit into even modest amp budgets and still give excellent power supply results. If the amp is small (5W/channel SE) then one will do. If higher power, then split the supply after the primary filter cap and use one for each channel. Further more Antique Electronic Supply has 100µf/450VDC axial lead capacitors (search for C-ET100-450) for only $4.20 each and the JJ multi-section caps (I've had very good results with these) dual 100µf/500VDC for only $11.75 each.

I guess all that I'm saying is that a good power supply doesn't need to cost a fortune. :$: People often times over look good parts because they are not trendy. Just my :2c: worth.

ok well first of all thank you soo much for your help... I am very greatful :mrgreen:

Ok... I have been deciding what I will do, and I think i will do either a KT77 or KT88 PP amp. I might do the 77 cuz i have heard them in a Peavey XXX guitar amp head and man the mids, treble, and bass are just incredible on it with those tubes(to my ears).

I will probably price things out for all the Push pull KT amps and see which one is more in my budget. Thank you so much for all your assistance. And If I need any help with finding the right parts, i know where to come :up:


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PostPosted: 05 Dec 2010, 23:55 
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Oh, lotsa posts since this AM!

Yeah, KT88 is the simplest answer :D

Cheers!

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PostPosted: 06 Dec 2010, 22:13 
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wait... ok so on the KT77 PP amp, did he make 2 of them for stereo purposes or something? does that mean if I want stereo, i must have double the tubes and 2 output transformers? Im sure thats what it means but I wana be sure...


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PostPosted: 06 Dec 2010, 22:50 
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wait... ok so on the KT77 PP amp, did he make 2 of them for stereo purposes or something? does that mean if I want stereo, i must have double the tubes and 2 output transformers? Im sure thats what it means but I wana be sure...
Yup. That's what it means. You may be able to build a single power supply and use a single twin triode as a driver for both stages (thus saving one tube and some power iron) but stereo means two PP output stages and two output transformers.

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