Aleph Ono Project (from PCB group buy)

[dhole]

Hi. If anyone is interested, I finally found the perfect red led that give the correct 1.0V at R67/R53 using the correct R5=6.8K. I got a few of these.

I'm looking for 1 quad of matched SK170GR, I have one set defective into my ONO.

Thanks in advance...

SB

Hi there

Just having the classic ono led issue. tried to now and have 1.24k over 67/53
have tried changing their values but the only thing that changes the reading is changing the Led. Any chance you could tell me the specs of the led you used please.
regards
dave

 

[ANADIGIT]

Hi, guy
How do I increse bass response of ONO ? because when I compared to CAT SL-1 result was ONO there's a less bass about 20%, why ?

What's type of 2SK170 on the MC stage ? GR,BL or V

Thanks
Anadigit

 

[Tarasque]

The type of 2SK170 can be either BL or GR. It is important that the total rurrent thrugh the fets is not too much so the drain voltage is around 5-10V of the four fets.

Base response can be improved by adding a 220u cap in parallel of the 10u coupling caps.

You also may check the values of thee RIA correction components.

 

[fschlenk]

Hi there,

my ONO just does not working any longer. I am reading the following voltage :
Q 24 E: 6,8 V
Q 14 E: 0,3 V
Q 15 D. 0,6 V
R67/53 Voltage: 1V
R 28 Voltage: 0,35V

What could be the problem ?

Thanks in advance and best Regards

 

[fschlenk]

Hi there,
problem solved.
Q24 ZTX 450 in the MC input was gone and Q6-2SA991 in the main circuit died as well.
Thanks for reading anyway. Probably this is useful for someone sometime.

 

[Marra]

Does anyone have a copy of the Xono service manual they could let me have a copy of? TIA.

 

[Marra]

R67 and R53 should be around 1.0 volt. I found that I could change R5 to 15K and this gave me a tenth of a volt more drop. What voltage does your R67 and R53 read?

I tried this and the voltage readings R53 & R67 has dropped to 1.18v from 1.24v and the voltage across the led is 1.78v. Do I need to drop it further by altering the values of R67 & R53? The 9110 still run quite hot.

 

[platon.rado]

hi do you have any more boards for phono preamp ono