Advice wanted on Aleph P1.7 build

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Hi,

I am stuck and could use some advice.

Jaap (a friend of mine - a retired "genius with a soldering iron" - does the actual building for me) started on an Aleph P1.7 for me 4-5 years ago. We bought all the parts from a Dutch supplier (who supplied KK PCB boards). This was before I started reading this forum and realised Nelson frowns on suppliers offering kits.
We had very little information and had no idea what we were doing (we bought a kit, right?!). To cut a long story short, our supplier went out of business, Jaap cannot read English and I knew very little about electronics. So when we ran into trouble we just left it on the shelf to finish another day.

In the past year or so I have tried to read as much as I can and am starting to understand what we are building. So, the day has arrived!

We had not realised that the volume control and input selection supplied were Chinese parts. (It looks identical to this one: Préamplification - LITE V3310 4ch - Contrôleur de volume 4 voies ou 2 voies XLR )
When I found out that the volume and input control were Chinese parts (of unknown quality), I asked Jaap to take the Aleph parts out of the box and just leave the Chinese parts, because I wanted to hear what they sounded like. I tried it as a passive pre (instead of my old Yamaha CX-1000 preamp) in my study and am now glad I took it out of the Aleph P1.7 build! It does have good solid bass, but the highs scream out of the speakers. Nothing refined about it.

Back to the Aleph P1.7.
We tested the finished Aleph boards, and they work.
I have not really heard them yet, just confirmed that they work. I now need to make a decision about input selection and volume control. I was leaning towards using the Dantimax boards, but after reading about lightspeed (I gather consensus is that it gives a better sound than resistor based systems) I am not so sure. I sent a message to Uriah, asking him if the boards he sells can be used for an Aleph P1.7 (where a 1K attenuator is required). He answered that it could not.

So now I am stuck. I am open to all suggestions.

Thanks for listening.

Albert


PS Enclosed an old photo of the Aleph P1.7 build with all the Chinese stuff in the Chinese box.
 

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I bought a stepped 100K attenuator, this is also giving me problems.

My best advice is to look at hificollective.com. They do some very nice standard potentiometers. You pay for what you get, I'm back to ALPS pots and they sound perfect to me.

I'm using a Pumpkin/Shuntky with an Aleph 4.
 
The very best passive preamp I've ever heard was an autoformer based one. It was remote controlled and used mercury wetted relays to switch between the attenuation taps on the autoformer. Completely transparent and maintained dynamics into the very low volume settings like I’ve never heard before.
 
Aleph P1.7 capacitors?

Hi,

I'm fresh on this pages, and registered in order to get some answers to my Aleph P1.7 and Aleph 5 construction.

I have a quite huge stock of Wima caps on the shelf, and want to know if there is a problem in using 1uF / 250V MKP10 blocks, instead of the stated 10uF Wima's on the original schema?

I think it will only have some infuence on the frequency response which will change from 0,5Hz to 5Hz in the lower regions...or not?

Can someone please help me on this?

Rgds,
John
 
Power cable

I am slowly but surely getting this build organised. Based on good experiences from others and patience in explaining by Mikkel I have decided to use the Dantimax boards.

I will place the PSU's (1 for each channel + whatever is required for the Dantimax boards), Dantimax Control2 and FrontPanel boards + OLED Display in a separate enclosure. The main enclosure will contain the Aleph P1.7 boards, as well as Dantimax Input2 and RelVol3.

I was planning on using a 4 or 5 pin XLR to bring 2 x 60V DC + SgnGnd + ChsGnd from the PSU enclosure to the main enclosure, but have just seen that the Neutrik XLR's are officially rated at 7.5 or 10A (which is fine because the Aleph P1.7 draws little current), but at 50V AC.
How big of a problem is this?

I would love to hear what have others used to get 60V DC from one enclosure to the next?

Thanks,

Albert

Enclosed a pdf of my design of the rear panel of the main enclosure.

Edit: The engraving is missing from the PDF. Left lower are XLR for Aleph and RJ45 for Dantimax. Others are main out (XLR and RCA), Tape in/out and 5 x input.
 

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