Differential to single ended... - Page 2

Bas Horneman · 12th March 2003, 09:48 AM

ROTFLMAO

Hi Frank..

I'll take your word for it..However..a pf86 is still 5 times cheaper than the svet ef86..

Call me cheap!

Regards,
Bas

Bas Horneman · 19th March 2003, 03:47 PM

Is the a 1meg grid resistor a problem for the preceding stage?

I am assuming that the differential op-amp stage is the first...and maybe only stage after the dacs...

So I guess I should ask if a 1meg impedance is a problem for the dac?

I saw the posts on the other dac thread here at tubes...saw figures like 6ohm...or are they talking about other things here?

Cheers,
Bas

fdegrove · 19th March 2003, 04:09 PM

Hi,

Quote:

Is the a 1meg grid resistor a problem for the preceding stage?

If the EF86 is the input of an amplifier I would lower it to 100K.

OTOH, if a stage is directly preceding it and wiring can be kept to a minimum, I would go for the 1Meg.

Quote:

So I guess I should ask if a 1meg impedance is a problem for the dac?

What are you feeding the EF86, you don't use a xformer?

Quote:

I saw the posts on the other dac thread here at tubes...saw figures like 6ohm...or are they talking about other things here?

The 6 Ohm R does the I/V conversion at the input of the xformer.

Cheers,

Bas Horneman · 19th March 2003, 04:14 PM

Hi Frank,

Thanks for helping.

Quote:

What are you feeding the EF86, you don't use a xformer?

I am thinking that what I am feeding the EF86 is the same signal that goes to the differential op-amps..NE5532. So I guess the I/V conversion..(If any) has allready taken place.

Essentially I am replacing the NE5532 with an EF86 differential stage.

Unfortunately I don't have a schematic of my cd player.

Cheers,
Bas

Bas Horneman · 27th March 2003, 08:56 AM

Last night I fired up my CD player with the PF86 differential output stage.

To my complete amazement it worked!!!!

Will borrow a digital camara next week and post pictures..

Sound improvement was not the day and night difference I was expecting. Instruments sound more like real instruments...was about the only improvement I heard...Bass seemed a little less

Still have some noise issues...I suspect the toroïdal power transformer...it's the same one I used for a preamp that made the same noise

Filament supply is DC...star earthing is being used.

Anyway...am a happy camper...

Cheers,
Bas

Bas Horneman · 27th March 2003, 10:24 AM

CCS is a depletion mode mosfet (DN2540) as used by K&K audio.

fdegrove · 28th March 2003, 01:47 AM

Hi,

Quote:

Still have some noise issues...I suspect the toroïdal power transformer...

If I may say so, try to avoid toroids in digital circuits.

Cheers,

Bas Horneman · 28th March 2003, 10:47 AM

Hi Frank,

Ofcourse you may say so.

But I had it lying about... :-)

And it is shielded magnetically by a mu-metal shield...electrostatic shield and outside the cd player.. :-)

And it made the same noise when in the preamp.

Cheers,
Bas

Bas Horneman · 29th March 2003, 10:10 PM

pics
http://home.zonnet.nl/horneman/pf86dif.htm

Jay · 31st March 2003, 01:41 PM

Hi Bas,

Glad to know your CDP is working

You seemed to be a purist, simple circuit fanatic. Then your biggest homework is in the DAC upward

27th March 2003, 08:56 AM	#15
Bas Horneman diyAudio Moderator Emeritus Join Date: Apr 2002 Location: The Netherlands Blog Entries: 18	Eureka...It works.. Last night I fired up my CD player with the PF86 differential output stage. To my complete amazement it worked!!!! Will borrow a digital camara next week and post pictures.. Sound improvement was not the day and night difference I was expecting. Instruments sound more like real instruments...was about the only improvement I heard...Bass seemed a little less Still have some noise issues...I suspect the toroïdal power transformer...it's the same one I used for a preamp that made the same noise Filament supply is DC...star earthing is being used. Anyway...am a happy camper... Cheers, Bas

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Driving differential ADC with single-ended source	suzyj	Digital Line Level	9	19th May 2009 08:39 PM
single-ended to differential?	gentlevoice	Digital Line Level	16	17th December 2008 07:18 AM
testing a single ended or differential topology	Stefanoo	Pass Labs	11	26th October 2007 06:59 PM
Converting from single ended parafeed to differential	dsavitsk	Tubes / Valves	9	12th July 2007 07:46 PM
Volume control + Single Ended -> Differential Amp	koolscooby	Solid State	2	6th April 2004 12:50 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read

12th March 2003, 09:48 AM	#11
Bas Horneman diyAudio Moderator Emeritus Join Date: Apr 2002 Location: The Netherlands Blog Entries: 18	ROTFLMAO Hi Frank.. I'll take your word for it..However..a pf86 is still 5 times cheaper than the svet ef86.. Call me cheap! Regards, Bas

19th March 2003, 03:47 PM	#12
Bas Horneman diyAudio Moderator Emeritus Join Date: Apr 2002 Location: The Netherlands Blog Entries: 18	Is the a 1meg grid resistor a problem for the preceding stage? I am assuming that the differential op-amp stage is the first...and maybe only stage after the dacs... So I guess I should ask if a 1meg impedance is a problem for the dac? I saw the posts on the other dac thread here at tubes...saw figures like 6ohm...or are they talking about other things here? Cheers, Bas

28th March 2003, 10:47 AM	#18
Bas Horneman diyAudio Moderator Emeritus Join Date: Apr 2002 Location: The Netherlands Blog Entries: 18	Hi Frank, Ofcourse you may say so. But I had it lying about... :-) And it is shielded magnetically by a mu-metal shield...electrostatic shield and outside the cd player.. :-) And it made the same noise when in the preamp. Cheers, Bas

29th March 2003, 10:10 PM	#19
Bas Horneman diyAudio Moderator Emeritus Join Date: Apr 2002 Location: The Netherlands Blog Entries: 18	pics http://home.zonnet.nl/horneman/pf86dif.htm

31st March 2003, 01:41 PM	#20
Jay diyAudio Member Join Date: Feb 2003 Location: Jakarta	Hi Bas, Glad to know your CDP is working You seemed to be a purist, simple circuit fanatic. Then your biggest homework is in the DAC upward

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)