Burning Amp BA-3

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oltos

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Caps for BA-3's C3/103

wdecho said:
I would like to share some information on my BA-3 SE build. I used a polypropylene 10uh Dayton capacitor that was left over from some crossover builds and I decided to change that first with some Elna Silmic 11. The harshness was gone and the soundstage really opened up as good as my tube preamp. I would have never thought that there was that much difference in the sound of capacitors. Give the Elna a try, Nelson thinks real highly of them and he should know. David
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Of course, Walt Jung's in-circuit measurements and his explanations of how capacitor dielectrics affect signal integrity seem perfectly plausible http://waltjung.org/PDFs/Picking_Capacitors_1.pdf . Why else would Nelson use those two polyproplyene ClarityCaps PWA series caps for C3 & C103 (though with custom copper lead outs rather than steel I was told by the rep)? But are you really sure that swapping out those Dayton polyprop caps with electrolytics of whatever brand improved the sound quality? I'm going for the ClarityCap 10uf ESA series, IF I can fit it on the board https://www.madisoundspeakerstore.c...0-mfd-esa-range-polypropylene-capacitor-250v/ I don't know about the 45mm length. I don't have the boards yet. Does anyone know if it will fit?
 
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Russellc

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wdecho said:
I would like to share some information on my BA-3 SE build. When I first did some serious listening I could not see that much difference in the sound than my Aleph 30 I just recently built, in fact I detected a little bit of harshness in the female vocals much like an A B amplifier. I knew it had to be in the front end because there is not much that could be wrong with the output stage with so little parts. In the front end there is not much except one capacitor per channel and it could also be some fake transistors. I once even bought some fake 2sk170 transistors from a seller in the USA. I used a polypropylene 10uh Dayton capacitor that was left over from some crossover builds and I decided to change that first with some Elna Silmic 11. The harshness was gone and the soundstage really opened up as good as my tube preamp. I would have never thought that there was that much difference in the sound of capacitors. Give the Elna a try, Nelson thinks real highly of them and he should know.

David
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Little confused, did you use it instead of Dayton, along with Dayton and what value did you use? Did you by pass with film?

Russellc
 
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wdecho

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Joined 2014
Hi Oltos, to my ears the Elna caps were an improvement in sound vs the Dayton. My speakers are very efficient horn speakers and with other speakers the Daytons could have sound alright. The Dayton caps I had in first are 45mm and I made them fit but it was not easy. You will have to bend the leads back to make them go in the holes but they should fit. The ClarityCap you are looking at are quality caps and they should sound fine. For 60 cents for 2 the Elnas sound great to me. I did put a film bypass cap in parallel with the Elnas but did not notice a real improvement in soundstage or sound. From what I understand the Dayton caps are Bennic and for crossovers they have worked fine.
 
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wdecho

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Joined 2014
Hi Russellc, I took the Dayton out and put in an Elna Silmic 11 10uf and wrote the post. I have since put a film bypass cap along with the Elna but did notice any real difference. The Elna is going to stay with the film as a bypass. You can spend a lot of money for better caps but for 60 cents for 2 of the Elnas they sound great. Maybe some of the big money caps would make it sound better but I'll never know. I might spend $20 for a cap if I thought it would help the sound but not hundreds. I read an article by NP saying how good the Elna Simlic 11's were for the money and ordered them long ago and since I had some on hand so I thought I would give them a try.
 
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oltos

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Pop Survey: Transformer EMI issues?

New BA-3 builders want to know: How many here had hum and/or noise issues that were later traced to their choice of transformer and/or because they did not initially shield it to contain its field radiation?

Of those using C-core and/or EI transformers, did you have these problems?

And was you transformer mounted in the same chassis as the BA-3 board?

Of those with these EMI problems, if it was solved by swapping transformers was it the toroid, the C-core or the EI that had the least noise and hum? And was that transformer in the same chassis with the BA-3 board?

On the other hand, did you solve your EMI problems by using Hitachi's FineMET https://www.hitachi-metals.co.jp/e/p.../hl-fm16-h.pdf or other sheeting available here Magnetic Field Shielding Materials ?

Did you cut it to size and either adhered it to the transformer and/or with the transformer in a steel case enclosing it http://www.antekinc.com/content/CA-xxx.pdf ?

Before replying, you may want to check out this
Electromagnetic shielding - Wikipedia, the free encyclopedia
and this short but informative thread
http://www.diyaudio.com/forums/parts/20484-transformer-toroid-vs-e-i.html
 
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oltos

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timbarnes said:
I put the CRC power supply in a separate chassis, on a 3' cable. I'm using an Antek toroid.
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Yes, I saw your build.
Nice! http://www.diyaudio.com/forums/pass-labs/195303-burning-amp-ba-3-a-36.html Pardon, the newbie question, but if I built two external supplies-one each for two BA-3 FEs-would placing the supplies side by side or stacked cause problems? If yes, what if each (Antek) transformer were placed in those (Antek) steel cases-and with a few strips of that Hitachi or Permalloy foil applied? I wouldn't ask otherwise, but space is somewhat limited where I plan to set things up. Btw, would you find this useful
http://www.rbannis.com/products/magnet/5.html ?
 
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Russellc

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Joined 2003
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oltos said:
New BA-3 builders want to know: How many here had hum and/or noise issues that were later traced to their choice of transformer and/or because they did not initially shield it to contain its field radiation?

Of those using C-core and/or EI transformers, did you have these problems?

And was you transformer mounted in the same chassis as the BA-3 board?

Of those with these EMI problems, if it was solved by swapping transformers was it the toroid, the C-core or the EI that had the least noise and hum? And was that transformer in the same chassis with the BA-3 board?

On the other hand, did you solve your EMI problems by using Hitachi's FineMET https://www.hitachi-metals.co.jp/e/p.../hl-fm16-h.pdf or other sheeting available here Magnetic Field Shielding Materials ?

Did you cut it to size and either adhered it to the transformer and/or with the transformer in a steel case enclosing it http://www.antekinc.com/content/CA-xxx.pdf ?

Before replying, you may want to check out this
Electromagnetic shielding - Wikipedia, the free encyclopedia
and this short but informative thread
http://www.diyaudio.com/forums/parts/20484-transformer-toroid-vs-e-i.html
Click to expand...

SUM-R toroidal. 24 + 24 @ 1000 VA. DEAD quiet. even with ear up next to horn, Woofer, whatever. Dead quiet. Transformer in Same chassis, DIY Store 5U chassis. BA-3 pre, same..... dead quiet. Antek Toroidal transformer (shielded) in same case, Dead quiet.

Russellc
 
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oltos

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y? said:
SUM-R toroidal. 24 + 24 @ 1000 VA. DEAD quiet. even with ear up next to horn, Woofer, whatever. Dead quiet. Transformer in Same chassis, DIY Store 5U chassis. BA-3 pre, same..... dead quiet. Antek Toroidal transformer (shielded) in same case, Dead quiet. Russellc
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I'll take your word for the quietude. But in a 5U chassis?
Deluxe 5U "Big Amp Chassis" (All Aluminum) V2 - Chassis ? I'm just building a BA-3 FE for my F4 amp. Sure,
I'd think that putting a toroidal transformer-shielded or not-in the corner of
a box that big and the PS board
http://www.diyaudio.com/forums/audio-sector/149672-universal-power-supply-pcb.html and the BA-3 board furthest away would be safe. But I was thinking of a box 12.3" d x 5.25" h x 9.6" L or these 2U chassis
Galaxy 288 (10mm Front) - Compact with Quasi Heatsinks - Chassis or
Galaxy 288 (3mm Front) - Compact with Quasi Heatsinks - Chassis So I guess I'd no choice but to do what timbarnes did and have the supply external to the BA-3 via a 3 ft. cable.
 
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Russellc

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oltos said:
I'll take your word for the quietude. But in a 5U chassis?
Deluxe 5U "Big Amp Chassis" (All Aluminum) V2 - Chassis ? I'm just building a BA-3 FE for my F4 amp. Sure,
I'd think that putting a toroidal transformer-shielded or not-in the corner of
a box that big and the PS board
http://www.diyaudio.com/forums/audio-sector/149672-universal-power-supply-pcb.html and the BA-3 board furthest away would be safe. But I was thinking of a box 12.3" d x 5.25" h x 9.6" L or these 2U chassis
Galaxy 288 (10mm Front) - Compact with Quasi Heatsinks - Chassis or
Galaxy 288 (3mm Front) - Compact with Quasi Heatsinks - Chassis So I guess I'd no choice but to do what timbarnes did and have the supply external to the BA-3 via a 3 ft. cable.
Click to expand...

Check 6L6 build thread its just like that. Its not the size of the box, its the heatsinks, which are minimal. Transformer is not stuck in the corner, its in the middle towards the front. The transformer is huge!

Surprising how hot this amp gets! Shoot, I put my BA-3 preamp in a 288 box! I hope you have huge heatsinks hanging off that little box or its going to not allow much bias...Those "Quasi heatsinks" are NOT going to handle the heat! Are you talking about a pre amp or amplifier?

If pre, mine is in a 288 chassis, with power supply inside, also dead quiet.
Russellc
 

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Russellc

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OK, I see you are after a FE! Here it is, I see no reason for the remote power supply, but whatever...
This is the Amp thread ya know! The transformer here is a shielded Antek. Pre is DEAD quiet as well.
Same chassis 6L6 used in his build thread, 3mm 288 I believe.
 

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Dennis Hui

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Hi,

I'm wondering what people are using for the C1, C2 caps? The outlines for them
look to be 10mm in diameter so the Elna Silmics likely won't fit.

There's a bit of space between the two outlines so I'm hoping 12.5mm ones can
still be used. There seem to be more choices in that size.

Any suggestions will be greatly appreciated.

Thanks,
Dennis
 
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oltos

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[Surprising how hot this amp gets! Shoot, I put my BA-3 preamp in a 288 box! I hope you have huge heatsinks hanging off that little box or its going to not allow much bias...Those "Quasi heatsinks" are NOT going to handle the heat! Are you talking about a pre amp or amplifier? [/QUOTE] I'm just building one BA-3 single-ended front end. No preamp. I think Nelson said that you want the bias between 6 and 12mA. That won't get very hot for a 288 box will it? I noticed your twisted pairs? This helps reject noise even though you don't have a two BA-3 boards wired as a diff amp for balanced stereo, which benefits from common mode noise rejection? Who makes your RCA jacks?
 
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