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04-18-2017 Post does not mapped to Knowledge Tree
anthony
Posts 137
Joined on 08-18-2014

Post #: 121
Post ID: 23169
Reply to: 23168
Filter Caps
Below are some images that show the locations of the various filter caps within the amplifier chassis.


The big cap for the First Stages is located directly below the 6E5P tubes...

Filter Caps 1.jpg



The big filter cap for the Bass Channel is adjacent to the Bass OPT (peeking through a hole):

Filter Caps 2.jpg




The filter caps for the DHT Channel, Upperbass Channel, Injection Channel are immediately below the respective OPT's with enough room between to make the panel meter connections...

Filter Caps 3.jpg




Below you will see the clusters of smaller caps for the Bias string (11 caps) and the Single Stages (4 caps including one yellow)...


Filter Caps 4.jpg



Below can be seen the relative position and orientation of the 5 OPT's.

OPT Positions.jpg





I will look into placing shielding between the OPT's and the tube sockets.  There are a few options and I need to think about the best way to implement them.

Thanks for the help so far.


04-18-2017 Post does not mapped to Knowledge Tree
Romy the Cat


Boston, MA
Posts 9,301
Joined on 05-28-2004

Post #: 122
Post ID: 23170
Reply to: 23169
Very good
Agree, it is very good. For the vibration isolation, I would worry only about the driver tubes. If you have some money to waste then you might look for ALNIC made tube sockets vibration dumpers. They are VERY effective and if you buy them in bulk then they are not too cost prohibitive. Be advised that the driver tubes are very microphonic when they are cold. As you just turn the amp it will be latterly ringing for a first few mins. It should be dead quite after 5-10 mins. The good question would be if I hear the sonic difference with and without the sockets vibration dumpers. It might be but I think it is more done for intellectual satisfaction.  You might rubber recouping via the stand-off for the top tube-caring platform. To make is absolutely crazy you might find (I have seen them) pneumatic inserts in the standoffs and then to use very light wires if loos wires to connect the tube sockets. This will be a great engendering treat but I am not convinced that it will give you tangible sonic advantages.


"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche
04-18-2017 Post does not mapped to Knowledge Tree
N-set
Gdansk, Poland
Posts 436
Joined on 01-07-2006

Post #: 123
Post ID: 23171
Reply to: 23162
Nichicons
Gentlemen, I can only hope to be wrong on the  air-borne feedback.
Actually your project Anthony made me think of coming back to my Staxquiades
project - a Milq inspired monster amp for my Stax headphones.
Do you have a source of big PSU Nichicons at a good price?
I'd need 10.000uf/500V

Thanks,

PS I have been practicing a big deal of this extreme acrobatics myself in my end of life phono construction,
just not on such an execution level as yours. I do recognize quite some methods I used myself, although I look
like a dirty DIY-er compared to you. I reached the understanding the sandwitched chassis should be the
best (I even wrote it here somewhere) but have not executed it so far. Vibroisolation is another story.




Cheers,
Jarek
04-18-2017 Post does not mapped to Knowledge Tree
anthony
Posts 137
Joined on 08-18-2014

Post #: 124
Post ID: 23172
Reply to: 23171
DigiKey
Jarek, the best source for these big Nichicon electrolytics that I could find was Digikey.  They were substantially less expensive than other sources that I tried but do ship from the US which is an added freight cost.  I purchased these a couple of years ago so things may have changed and there may be less expensive sources, but I will not buy that sort of stuff from eBay or smaller vendors because I want to know that I am getting the genuine article.

04-19-2017 Post does not mapped to Knowledge Tree
N-set
Gdansk, Poland
Posts 436
Joined on 01-07-2006

Post #: 125
Post ID: 23173
Reply to: 23172
Iron?
Thanks! And who is winding your signal iron? Pieter?



Cheers,
Jarek
04-19-2017 Post does not mapped to Knowledge Tree
anthony
Posts 137
Joined on 08-18-2014

Post #: 126
Post ID: 23174
Reply to: 23173
No, no Pieter
Lucas Cant from Black Art Automation in Melbourne.  I cannot recommend him highly enough.
04-23-2017 Post does not mapped to Knowledge Tree
anthony
Posts 137
Joined on 08-18-2014

Post #: 127
Post ID: 23182
Reply to: 23166
EM Shielding, do or don't?
 anthony wrote:
...you've got me thinking about this now.  I'll talk to some people here and see what they think, but it should be easy enough to place a shield between the OPT's and the tube bases.

Thanks for bringing it up.  I am looking for other angles to view the design, and yourself and Jarek have been very helpful.



I've talked to my advisers here about the potential EM induction at the tube sockets from the various OPT's situated beneath.  It is not easy to see on the sketches, but absolute minimum separations are 60mm for the smaller, high frequency OPT's and 75mm for the huge Bass OPT.  Basically, because the voltages are relatively low at about 200VDC those minimum separations are expected to be "plenty".  

If this was a 211 amp with 1800V on the plate then there would definitely be an issue even at 40cm...shielding would be essential.

So I am going to go without shielding in those locations for now.  If I have problems then I should be able to retrofit something, but fingers crossed that will not need to happen.

Thanks for bringing it up guys.
04-23-2017 Post does not mapped to Knowledge Tree
Paul S
San Diego, California, USA
Posts 2,056
Joined on 10-12-2006

Post #: 128
Post ID: 23183
Reply to: 23182
Mock-up
That's good news, Anthony; no sense doing something like that just to do it.  If you really wanted to, you could fire up the trannies and measure the fields.


Best regards,
Paul S
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