Aleph P 1.7 in Multichannel

[Lucas_G]

Hi Pass-Fans,

After having build Aleph 5 power amplifiers, my next project will be an Aleph P 1.7 pre-amplifiers.
I found a lot of info on this forum, however I still have one question:

I would like to make this preamp ready for multichannel. For this I will use a 6 channel volume-control.

Is it absolutely neccesary to use 3 boards (6 channels) of Aleph P preamps, therefor making all channels active?
Or could I use only one board (2 channels) of Aleph preamps, and leave the other 4 channels totally passive?

My SACD/DVD player has 6 channel analoque outputs. I don't think the quality of the other 4 channels is as important to me as the quality of the 2 front (stereo) channels.

Has anybody build such a preamp with 2 active and 4 passive channels?

Regards,

Lucas.

 

[jleaman]

i would say 3 board 2 channels per board = 6 channels. Sounds like a neat ideas As im starting to look at a project for my uncle ill work on this part too..

 

[Lucas_G]

3 boards is of course always a good solution, but also more expensive and more work...

Is there anybody who has done the 2 channel active / 4 channel passive solution?

Any suggestions?

Lucas.

 

[Oltremare]

Hi Lucas,
i have started to build a multichannel (5+1) preamplifier using the Aleph P 1.7 circuit. I have alredy purchased the PCB from Krjstian (nice, fast, and kind person) that are made very very well.
Yes, you can do 2 active channel and the rest passive but i think you make a "spaghetti jam" preamplifier. If you want to listen DVD video perhaps you can make it but if you want to listen good music the best way is make 6 active channel. In particular with SCAD or DVD Audio, che center chanel must be homogenous with the front channel. Normaly the passive preamplifier have a bad sound for me (probably for some impedance problems) and you risk to have a bad front sound (sure different between front and center channel) .
I know that Aleph P is expencive but if you make some search on the web you can find all components with good price. For example i have ordered many components at http://www.reichelt.de. I have ordered to RS Component only the IRF610, the relays, and the toroidal trasfo (RS is more expensive but in http://www.reichelt.de i hadn't find them). Now i am working to make the logical circuit for remote control for imput select and volume regulator. If you are interest about this, i can make a post with the circuit that now is on my breadboard.

Bye

PS. sorry for my bad english

 

[Lucas_G]

Hi Lucas,
i have started to build a multichannel (5+1) preamplifier using the Aleph P 1.7 circuit. I have alredy purchased the PCB from Krjstian (nice, fast, and kind person) that are made very very well.
Yes, you can do 2 active channel and the rest passive but i think you make a "spaghetti jam" preamplifier. If you want to listen DVD video perhaps you can make it but if you want to listen good music the best way is make 6 active channel. In particular with SCAD or DVD Audio, che center chanel must be homogenous with the front channel. Normaly the passive preamplifier have a bad sound for me (probably for some impedance problems) and you risk to have a bad front sound (sure different between front and center channel) .
I know that Aleph P is expencive but if you make some search on the web you can find all components with good price. For example i have ordered many components at http://www.reichelt.de. I have ordered to RS Component only the IRF610, the relays, and the toroidal trasfo (RS is more expensive but in http://www.reichelt.de i hadn't find them). Now i am working to make the logical circuit for remote control for imput select and volume regulator. If you are interest about this, i can make a post with the circuit that now is on my breadboard.

Bye

PS. sorry for my bad english

Hi Oltremare,

I am defintely interested in your circuit!

Since I am busy building the Doed Dac and upgrading my Philips 963 SA player, I still haven't started building a preamp, but my thoughts keep turning to a multichannel Aleph P 1.7

How are you going to fit everything into an enclosure? Are you building a seperate enclosure for the PSU? How many transformators will you use for 6 channels?

I have also bought a lot of transistors from Reichelt and I already did some matching...

What is still giving me a headache is the choice of volume-controll.
With 6 channels and a balanced version for the front-channels, one needs already an Elna or Dact pot with 8 poles... Bloody expensive!

I am also curious whether the Burr-Brown PGA 2310 volume control could be any match? It is an op-amp of course, so does it sound less good than the dicrete Aleph? If it would sound good, it does deliver a lot of features, and it would be very easy to build it in multichannel... Does anyone have experience with this?
The link is: http://www.ub-audio.com/produkte/vc.htm

Regards,

Lucas.

P.S. Il tuo Inglese non è male! Dove abiti in Toscana?

 

[Edwin Dorre]

I would like to make this preamp ready for multichannel. For this I will use a 6 channel volume-control.

Hi Lucas,

I have been thinking about this project as well. I own a real Pass Labs Aleph P (not DIY) and like the sound of it. I have build an Aleph-X and have just ordered a Denon DVD-2900. So a real good multichannel pre-amp would be great to amplify the signal from the Denon 2900 to my amps. I now use a Denon 3802 home theatre amp for this, but I am looking forward to replace this. I will read this thread with great interest.

Perhaps we can team up!

Edwin

 

[Oltremare]

Hi Lucas,
Philips 963 good player!
At the moment i haven't decided the enclosure, probably i will use only one. In Italy there isa a specialized firm (www.hifi2000.it) that produce enclosure for HiFi in Rack standard. The biggest one of "linea pesante" series could be enough for all circuits. For the supply i will use one toroidal trasfo for audio (2X30V 300VA) and another one for logical and relays circuits (12V 50VA).
The power supply circuit is only one for each channel since transfo to electolytic capacitor. For diode bridge i will use 4 ultra fast diodes (BYV79) and for capacitors, 2 Siemens Sikorel 4700uF 100V. After them, the supply board are 3 (one each 2 channel).
For volume control i will use 3 double ALPS motorized potentiometer drived by remote control (for remote i use a Kit bought at http://www.futurashop.it/images_la/7100-FT205K.jpg) with adapted relay circuit.
The kit is complete with TX circuit in a little enclosure easy to assemble.
With the same RX circuit i drive the imput selector circuit.
Unfortunately in this moment i am away (now i am in Milan for job) and i don't have with me the scheme of relays, volume regolator and imput selector. Wen i will be at home i will make a new post with all scheme.
Unfortunately i don't know the BB PGA2310...i will go to see it in www.ti.com. My electronics know how perhaps is not enoguh to use it

Bye!

PS. si vivo in toscana, per la precisione in maremma. Tu come mai conosci l'italiano?