Pass D1 output stage.

pro · 12th May 2004, 03:02 PM

Some one knows if it is possible to apply the output stage of the Pass D1 to a CD player that it uses 4 BB pcm1702 in place of the BB pcm63?
The only difference between two me seems to be the output current that is 1,2 mA in place of 2 mA.
Thanks.

till · 18th May 2004, 10:21 AM

i would expect it works, as it works also with AD1865
http://www.diyaudio.com/forums/showt...625#post383625

CheffDeGaar · 18th May 2004, 01:08 PM

Hi,

Just scale R27 and R34 from original schematic to give you the wanted I/V conversion ratio :

2mA in 1K5 give you 3V FS, so use 2K5 for R27 & R34...

pro · 18th May 2004, 01:40 PM

Thanks guys.
To this point, if not mistake, task that they go replaced in agreement also cap.C15 and C16.
Still a question.
Thoughts that replacing ghi IRF 610 with of the MPV3306, or the 2sk389 can go the same one well? I ask, why of these transistors I have some in house already of the selected braces, therefore I would avoid to buy of others.
Thanks again.

CheffDeGaar · 18th May 2004, 02:04 PM

Quote:

Originally posted by pro
Thanks guys.
To this point, if not mistake, task that they go replaced in agreement also cap.C15 and C16.
Still a question.
Thoughts that replacing ghi IRF 610 with of the MPV3306, or the 2sk389 can go the same one well? I ask, why of these transistors I have some in house already of the selected braces, therefore I would avoid to buy of others.
Thanks again.

Oups ! Yes you're right, I just forgot about the LP filter.. Just recompute the cap's values accordingly

Don't know the MPV3306. Same as Zetex' ZVN3306 ? If yes, it should work, but be careful about dissipation issues. I don't know either how it will sound with a 3306... Just test.

2SK289 should work too, but chose the right grade to withstand the bias current. In this case the gate voltage should be negative to achieve 0V at the source. Just check this thread for additionnal info :

I/U stage D1 clone with 2sk389 finetuned...

Hope this helps

pro · 18th May 2004, 02:05 PM

Hop! I am sorry.
I wanted to say ZVN3306A.

stefanobilliani · 18th May 2004, 04:50 PM

Quote:

Originally posted by pro
Hop! I am sorry.
I wanted to say ZVN3306A.

Works fine.

pro · 26th May 2004, 09:20 AM

One other question.
Because it's output will run in unbalanced mode, is a CCS needed in place of R26 and R33, or well therefore as it is.
Thanks.
Pro.

stefanobilliani · 26th May 2004, 11:56 AM

Works well as it is . CCS isn't necessary but you can try it . IMHO the CCS changes a little the sound character , and gives to it the sensation of more articulation, but very little.

I just tried the buffers with P-channel ZVP3306A and works fine.

pro · 26th May 2004, 12:14 PM

Thanks Stefano.

12th May 2004, 03:02 PM	#1
pro diyAudio Member Join Date: Feb 2004 Location: Milano	Pass D1 output stage. Some one knows if it is possible to apply the output stage of the Pass D1 to a CD player that it uses 4 BB pcm1702 in place of the BB pcm63? The only difference between two me seems to be the output current that is 1,2 mA in place of 2 mA. Thanks.

18th May 2004, 01:08 PM	#3
CheffDeGaar diyAudio Member Join Date: Feb 2003 Location: This Universe, I think	Hi, Just scale R27 and R34 from original schematic to give you the wanted I/V conversion ratio : 2mA in 1K5 give you 3V FS, so use 2K5 for R27 & R34... __________________ /Cheff - Falling feels like flying, until you hit the ground

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18th May 2004, 10:21 AM	#2
till Banned Join Date: Apr 2002 Location: Germany, Clausthal	i would expect it works, as it works also with AD1865 http://www.diyaudio.com/forums/showt...625#post383625

18th May 2004, 01:40 PM	#4
pro diyAudio Member Join Date: Feb 2004 Location: Milano	Thanks guys. To this point, if not mistake, task that they go replaced in agreement also cap.C15 and C16. Still a question. Thoughts that replacing ghi IRF 610 with of the MPV3306, or the 2sk389 can go the same one well? I ask, why of these transistors I have some in house already of the selected braces, therefore I would avoid to buy of others. Thanks again.

18th May 2004, 02:05 PM	#6
pro diyAudio Member Join Date: Feb 2004 Location: Milano	Hop! I am sorry. I wanted to say ZVN3306A.

26th May 2004, 09:20 AM	#8
pro diyAudio Member Join Date: Feb 2004 Location: Milano	One other question. Because it's output will run in unbalanced mode, is a CCS needed in place of R26 and R33, or well therefore as it is. Thanks. Pro.

26th May 2004, 11:56 AM	#9
stefanobilliani diyAudio Member Join Date: Jun 2002 Location: Italy	Works well as it is . CCS isn't necessary but you can try it . IMHO the CCS changes a little the sound character , and gives to it the sensation of more articulation, but very little. I just tried the buffers with P-channel ZVP3306A and works fine.

26th May 2004, 12:14 PM	#10
pro diyAudio Member Join Date: Feb 2004 Location: Milano	Thanks Stefano.

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