Aleph 60 building thread

[PKI]

Got it!
And from what I heard I need to find a replacement for my Infinity Renaissance 80. I love them, but Aleph 60 is not enough for them in bass section. So... thinking of OB with Alpha's 15 on the bottom and AN 8"-10" for mid and probably some tweeter.
but this is another story

 

[sakellogg]

naah

just leave it as is ( I mean AC gain) and enjoy in listening

later , when your understanding ( read while you are listening ) of circuit operation rise ..... then make measurements and alter what you want

song - any Hendrix or Zappa , longer than 7 minutes

IMO very wise.

 

[PKI]

I looked into zvp3310 data sheet and found operation temp is up to +150c, is it a case temp or crystal? Even I made a heatsink for them I can not touch them, did someone try them and have the same issue?

 

[PKI]

Ok, it's been 10 days am listening to my aleph and sadly I think that something is wrong.
It sounds very "flat" and fatiguing. There is dynamics and good freq range, but looks like maybe it is too much distortion. It looks/sounds like it is even hard for the amp to drive 90+db 8ohm pioneer hpm's. it is not clipping, but when music is more difficult and loud mid frequencies get muddier.

I measured most points and the look fine to me. I bias it 0.45mA per device(x6). DC offset is ~45mV. If I play 100hz sine with 12mV amplitude i measure 1.2V int 8ohm speakers. I tried to adjust/measure AC gain but my Voltmeter just can't measure such low values of AC V across output resistors. I have a USB oscope which is terrible, but I'll try to solder something as probes ends and us it tomorrow.

Guys, I am totally lost and would appreciate any help, Please!

 

[AudioSan]

0.45mA bias pr device??? that is nada. do you meen 450mA?

 

[PKI]

Oh, yes, sorry.

 

[AudioSan]

whats your rail voltage with load?

 

[PKI]

+/-32.8V

 

[AudioSan]

okei. so that is about right.

 

[AudioSan]

hmmm. tricky one. it sounds like a input problem. but i can be wrong.

 

[PKI]

Nobody? :-(

 

[Zen Mod]

make this and try , connecting it at amp output - maybe you're having oscillation on output

if LED's are lit , it's there

 

[PKI]

Thanks! I have an usb oscope, can I check oscillations with it?

 

[Zen Mod]

is it able to cover at least up to 10MHz ?

 

[PKI]

Good enough? http://www.easysync-ltd.com/product/520/ds1m12.html

 

[Zen Mod]

nope if "Analog Bandwidth 250KHz" is what I'm understanding

make that two led thingie

put 1uF solid cap in parallel to C19 (Service Manual nomenclature)

 

[PKI]

Ok, and btw, I have C20=12pf not 10pf. Is it bad?
How critical capacitors and resistor values in that 2LED thing? I do not have exact values?
1nf before I connect a thing or instead connecting it?

 

[Zen Mod]

I said - service manual nomenclature

it's 220uF , cap for Aleph CCS modulatioon

 

[PKI]

Ops, sorry, yep. I already have 10nf there, ok?
Another thing: I thing I have some hum in idle out of the speakers. I am not sure if it is 60hz(120) from PSU or not. I do not have ground loops though.

 

[Zen Mod]

too many things in same time

I couldn't cope with your mix up between one schmtc nomenclature and different pcbs and confusion in your head ;

whatever - what you can do is to make proper original front end ( not with those ZVP or something like that ) then start from there

every change will be change from original and you'll know is it for better or for worse