I saw only one person update their wiki.
Can those people who received the PCB do everyone a favor, update the wiki, so we know the status of shipping.
Thanks😎
Can those people who received the PCB do everyone a favor, update the wiki, so we know the status of shipping.
Thanks😎
I already used a 5K Poti in my previous preamp and according to the text from Nelson Pass in Bosoz it gives the best performance and the best frequency response.
One question:
what kind of transformer do we need here?
The 2 secondaries are not symmetric.
I will be using these trafos with double screaning, isolation between secondary and primary, magnetic and electrostatic screaning.
If we order more than 5 pieces we can order them custom made.
They are from www.schuro.de and cost 33,00 Euro for 65VA.
One question:
what kind of transformer do we need here?
The 2 secondaries are not symmetric.
I will be using these trafos with double screaning, isolation between secondary and primary, magnetic and electrostatic screaning.
If we order more than 5 pieces we can order them custom made.
They are from www.schuro.de and cost 33,00 Euro for 65VA.
Attachments
I will just use two trafo's. One 2x55v, 160VA and one 2x12v 160VA. Using two PSU boards, one secondary from each trafo, goes to each board. If using one PSU board, just parallel the secondaries on both trafo's.
Steen🙂
promitheus said:
Good question, but more importantly-- does anyone know the max AC voltage that can be used with the low voltage negative power supply board? Knowing this will make it much easier to get a suitable transformer.
My negative supply rail is -20V DC, but it isn't necessary to go that high. I wouldn't go any less than -10V DC, and suggest -12 to -15V DC as a reasonable range for great performance.
I wanted to play with various power supply configurations and see what results I could get, so I left my self with extra voltage to play with just in case I needed it. I am currently running dual mono supplies, with separate discrete soft recovery diode bridges for each rail, followed by a CRC filter with 10,000uF per rail, plus a discrete voltage regulation stage. That then feeds into the RC filter in the gain circuit. The result: absolute dead silence with the volume control at maximum, and fantastic channel separation. This supply is just plain silly overkill, but for me it was kinda like climbing Everest, it did it because it could be done.
I must admit, now that I have seen Kari's boards, I wish I'd got in on the GB so I could rebuild it all pretty like, instead of the perfboard version I have now.
Cheers, Terry
I wanted to play with various power supply configurations and see what results I could get, so I left my self with extra voltage to play with just in case I needed it. I am currently running dual mono supplies, with separate discrete soft recovery diode bridges for each rail, followed by a CRC filter with 10,000uF per rail, plus a discrete voltage regulation stage. That then feeds into the RC filter in the gain circuit. The result: absolute dead silence with the volume control at maximum, and fantastic channel separation. This supply is just plain silly overkill, but for me it was kinda like climbing Everest, it did it because it could be done.
I must admit, now that I have seen Kari's boards, I wish I'd got in on the GB so I could rebuild it all pretty like, instead of the perfboard version I have now.
Cheers, Terry
Illusus said:
I was just wondering if anything had come of this. I believe I am going to go the relay stepped attenuator route. So this seems to be one of the better options. Anyone else interested?
Dave
Coulomb-
Any update on the parts kit? Still waiting on the transformers I suppose? Just checking...
Any update on the parts kit? Still waiting on the transformers I suppose? Just checking...
metalman said:
Metalman/Terry- I saw your preamp a few months ago on the relevant thread, looked great to me. Is the design from Kari's boards essentially the same (X-CCS-BOSOZ) if one uses the whatchamacallit option (other than your overkill power supply)?
Yes, if you include the cascode, you have the circuit I used, which I can't rave about enough although I suspect I am somewhat biased towards my own creation. However, I have had a few friends audition it in their systems where it displaced units costing a few thousand dollars, and had quite a time getting mine back. A couple of those people have hounded me since to build one for them, but I told them they'd either have to go buy a Pass Labs preamp or build one themselves. I am within striking distance now of having my Aleph-X's finished and I can't wait to see how they integrate with my preamp.
BrianDonegan said:
Yes I am still waiting for the transformers for Hong Kong, 3 more weeks I think.
I will have a few transformers left over, maybe 6 units. When I know for sure I will post the actuall quantity, the price will likely be $22 US plus shipping.
Regards
Anthony
steenoe said:
Hello Steen, those look good for about 120 Watts Class A each in Mono config, is that about right?
Regards
Anthony
Coulomb said:
Anthony, you dont have any left over kits aswell?
I know I'm late, but I'd like 2 ea amp/psu kits if you have.
Thats about right, Anthony. I go for 2x100 watt's, biased as hard as my wall-outlet will permit😀 I am getting tired, dragging those amps around😉 My back is starting to hurt🙂 Hope to finish them soon. I have to admit that the A-x's isnt excactly the easiest amp I have built
I almost thought they were gonna kill me, arrgh
Steen😎
SvErD said:
No spare kits at this time though I am thinking about a make up order for a dozen kits for latecomers. Prices will be higher though due to low quantity purchases.
Regards
Anthony
DaveM said:
Well, Dave, I'm finding myself very, very busy these days, most likely too busy to take care of the GB myself, at the moment. However, Mikkel is a very articulate and seemingly reasonable man which assures me that anyone willing to set up the GB will have no problem dealing with him, he seemed very willing to help when I made the initial inquiry. Also, Mikkel has been volunteerily checking in on my project's progress. One of only a handfull of people I've ever dealt with to check in on their customers after the sale.
BTW, I've recently tested the kits I've received from Mikkel (basically, the kits form a complete, passive pre-amplifier) and everything works as it should, I'm a little tempted to keep it as a passive pre based on its current performance but the Zen-aleph needs more gain for full out rock sessions
.Leftover Boards and Parts Kits
Anthony, Kari,
IF there is a set of pre-amp and power supply boards available, I would like to purchase them. Likewise for the parts kits.
Barring that, perhaps there is enough interest to generate another GB? Keep us posted if that happens.
Coulomb said:
Anthony, Kari,
IF there is a set of pre-amp and power supply boards available, I would like to purchase them. Likewise for the parts kits.
Barring that, perhaps there is enough interest to generate another GB? Keep us posted if that happens.
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