Hi guys,
Here is my new Aleph P preamp. Yesterday I received the last parts, and I immediately knew that I'll have a long sleepless night of soldering, cuting, drilling and fixing. So now it's finally done. It's just a test version, because I didn't want to make a mistake like I did with my Aleph 5 (putting it all together and then screwing around with removing hum).
I pluged it in and wonderfull music started to play. The sound is really awesome. It's clear, detailed, tight and firm bass and awesome dinamics. Toroid is 150VA 2x60V, "special" mix of Dale, Riken and Caddock resistors are used, and of course Black Gates as coupling caps. 1000uf caps in PS filtering are black Elnas, and on preamp board they are Panasonics. For the testing purposes I've used 50K Alps blue pot until my balanced stepped attenuators are soldered. All of the signal wires are Cardas (even the PS wires).
But there is a problem with hum while turning the volume up. What could cause this? Any suggestions are welcome before I start desoldering and experimenting.
Here is my new Aleph P preamp. Yesterday I received the last parts, and I immediately knew that I'll have a long sleepless night of soldering, cuting, drilling and fixing. So now it's finally done. It's just a test version, because I didn't want to make a mistake like I did with my Aleph 5 (putting it all together and then screwing around with removing hum).
I pluged it in and wonderfull music started to play. The sound is really awesome. It's clear, detailed, tight and firm bass and awesome dinamics. Toroid is 150VA 2x60V, "special" mix of Dale, Riken and Caddock resistors are used, and of course Black Gates as coupling caps. 1000uf caps in PS filtering are black Elnas, and on preamp board they are Panasonics. For the testing purposes I've used 50K Alps blue pot until my balanced stepped attenuators are soldered. All of the signal wires are Cardas (even the PS wires).
But there is a problem with hum while turning the volume up. What could cause this? Any suggestions are welcome before I start desoldering and experimenting.
Attachments
Wow! Very, very nice! I see you decided to use a pot instead of an attenuator and decided to go with a fixed gain resistor. Mine is still a few weeks away. I send the front and back panels out to Frontpanel Express to get the panels engraved. All my boards are built and just awaiting the chassis work. I also see you used Blackgate type "N" capacitors. Good Show and congratulations to you. Job well done!
Thanks for the comments kilowattski, I hope we'll se your Aleph P soon.
I used fixed gain resistor, it's Caddock 820R 0.1%. I've just put a pot for the volume control to see if preamp is working at all. I'm waiting for Dale RN60D resistors to come so I can solder my stepped attenuators and then I hope I'll se the influence of the attenuator.
I still have a lot to do. Anodizing case, stepped attenuators, input selector with relays and I have to make it balanced.
I used fixed gain resistor, it's Caddock 820R 0.1%. I've just put a pot for the volume control to see if preamp is working at all. I'm waiting for Dale RN60D resistors to come so I can solder my stepped attenuators and then I hope I'll se the influence of the attenuator.
I still have a lot to do. Anodizing case, stepped attenuators, input selector with relays and I have to make it balanced.
I Like Those Chassis Brackets
bbakota2000,
Gee those right-angle support brackets on your chassis look very similar to mine!
http://www.geocities.com/super_bq/BLS1.html
What make is your attenuator? I'm in the market for an 8 gang stacked one for 'stepped' ladder instead of series in balanced L/R control.
BQ
bbakota2000,
Gee those right-angle support brackets on your chassis look very similar to mine!
http://www.geocities.com/super_bq/BLS1.html
What make is your attenuator? I'm in the market for an 8 gang stacked one for 'stepped' ladder instead of series in balanced L/R control.
BQ
Banned
Joined 2002
Re: I Like Those Chassis Brackets
It is an old ITT/Beyshlag attenuator with silver contacts. I got two of them 4 gang/25 position from my friend for free. It was used in an old military equipment and it is pretty damn good. I'll also make ladder balanced. It will be a lot of soldering.
You are probably using some "fancy" foil caps. I used Black Gates N type, and everybody who tried them said it's way better than most of the foil caps (not very expensive ones). My guess is; if you're not willing to spend $500 and more for the caps in Aleph P, Black Gate N is the only choice. These Black Gates were something like $5 a piece.
Super_BQ said:
It is an old ITT/Beyshlag attenuator with silver contacts. I got two of them 4 gang/25 position from my friend for free. It was used in an old military equipment and it is pretty damn good. I'll also make ladder balanced. It will be a lot of soldering.
JasonL said:
You are probably using some "fancy" foil caps. I used Black Gates N type, and everybody who tried them said it's way better than most of the foil caps (not very expensive ones). My guess is; if you're not willing to spend $500 and more for the caps in Aleph P, Black Gate N is the only choice. These Black Gates were something like $5 a piece.
Banned
Joined 2002
Banned
Joined 2002
Nice job JasonL. IRF610 doesn't need heatsink at all.
I read this thread: http://www.diyaudio.com/forums/showthread.php?postid=358954#post358954
so I decided to use Black Gates. Something better is much more expensive and they don't fit on the Kristijans boards. Too bad. Maybe one day I'll see about trying some other caps, but for now the sound is just too good to be true.
Are those BC components caps. I remember one guy from PassDIY gallery said he changed Solen MKPs to BCcomponent polypropilens and they sound much better (in Aleph P of course).
How will you implement LCD? Is it some preasembled kit or you're making one on your own?
I read this thread: http://www.diyaudio.com/forums/showthread.php?postid=358954#post358954
so I decided to use Black Gates. Something better is much more expensive and they don't fit on the Kristijans boards. Too bad. Maybe one day I'll see about trying some other caps, but for now the sound is just too good to be true.
Are those BC components caps. I remember one guy from PassDIY gallery said he changed Solen MKPs to BCcomponent polypropilens and they sound much better (in Aleph P of course).
How will you implement LCD? Is it some preasembled kit or you're making one on your own?
HI bbakota2000
Nice work ,it realy look nice . I purchased the same board from Kristijan but I having problem with some value . I would like to ask for some help .
First please let me know if I use N type of BG 10uF 35V if is OK or I need higher voltage . I read some were 35V would be OK but I want to be sure before I order the parts .
Second please let me know the value of R36 , I see you use resistors there . I will use 60-0 V power supply .These info for the capacitors if 35V would be OK .
I would like to ask for help ,with out help I can't go on to finnish the preamp .
Regards
Nice work ,it realy look nice . I purchased the same board from Kristijan but I having problem with some value . I would like to ask for some help .
First please let me know if I use N type of BG 10uF 35V if is OK or I need higher voltage . I read some were 35V would be OK but I want to be sure before I order the parts .
Second please let me know the value of R36 , I see you use resistors there . I will use 60-0 V power supply .These info for the capacitors if 35V would be OK .
I would like to ask for help ,with out help I can't go on to finnish the preamp .
Regards
gaborbela said:
35V is OK. Highest voltage at the output caps is around 27V, at input caps is half of that. I tried 800R resistor for R36, but the gain was too low so now I'm using Caddock 280R.
If you are intersted in 5K double ladder type stepped attenuators from my preamp let me know (bbakota2000@yahoo.com).
enclosures
I found some enclosures for a Pass Preamp on ebay!
Here’s the link to them:
http://cgi.ebay.de/Pass-Labs-DIY-XB...ryZ12050QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
I found some enclosures for a Pass Preamp on ebay!
Here’s the link to them:
http://cgi.ebay.de/Pass-Labs-DIY-XB...ryZ12050QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
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