Search found 76 matches

by karatestu
Tue Oct 23, 2018 8:27 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Thanks for your input Wolfgang. I am not adverse to putting in a buffer and will eventually try one i think.

As far as the article goes, i dont know enough to say if its right or wrong. Just thought it may prompt some discussion from you more learned members.

Cheers, Stu.
by karatestu
Tue Oct 23, 2018 3:45 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Anyone fancy casting an eye over this. Shows one channel of dac, dc blocking, volume control and input stage of power amp. I have not included the capacitance, resistance and inductance of cables etc cos I don't know what they are. Anything I can improve on (except reducing coupling cap value) ?????...
by karatestu
Tue Oct 23, 2018 2:51 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Just read https://www.soundstageultra.com/index.php/features-menu/general-interest-interviews-menu/311-what-s-wrong-with-digital-volume-controls Puts me off digital volume control but then I know naff all about it. Preamps are to be avoided if possible - when I removed my Avondale preamp board it wa...
by karatestu
Tue Oct 23, 2018 2:10 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

TDA1305 Dac chip definitely has 2.5V DC on its output. I just checked again.

So I cant get rid of the coupling cap :( Can still lower it to 1uf and not have audible bass roll off ?
by karatestu
Mon Oct 22, 2018 7:27 pm
Forum: Beginners
Topic: Cathode follower buffer
Replies: 10
Views: 1167

Re: Cathode follower buffer

Oh, sorry Ed. Have not checked email recently. Yes i would still like it.

Money will be sent tomorrow.

Many thanks, stu
by karatestu
Mon Oct 22, 2018 7:19 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

I thought so. Thanks for clearing that up Nick. I will keep the dac as is. I already pimped up the decoupling and vref cap with oscons years ago. Gave each power supply pin (3 of) its own psu and pfm flea reg on the most important one and a sprinkling of capacitance multipliers. Next thing i will do...
by karatestu
Mon Oct 22, 2018 3:02 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Well I could do that I suppose. I have found the i2s lines (Bitclock, wordclock and data) between SAA7376 decoder chip and TDA1305 dac chip.

Its a lot of buggering about though. :roll: What do i need ? Some sort of SPDIF chip ?

Stu
by karatestu
Mon Oct 22, 2018 2:49 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Hi Wolfgang, I am pretty sure it has 2.5V DC on the dac output but then I might have measured wrong with my DMM. I agree that no cap is best if possible to do so. I will measure again. NVA amps are like no other solid state amps I have come across. Richard Dunn the designer states that he intentiona...
by karatestu
Mon Oct 22, 2018 2:40 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Thanks Phil,

Oooo, reading that I am not so sure about adding more of them in the chain. I don't know. Suck it and see I suppose. Not cheap to try though. I do have a pair of the 3.3uf spare that I could rob for a bit just to try.

Stu
by karatestu
Mon Oct 22, 2018 2:24 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

How about a couple of these babies ….

https://www.ebay.co.uk/itm/1-5uf-Paper- ... rk:23:pf:0

I use a 3.3uf size of this cap as a high pass filter for my tweeters. Does a good job in that role :lol:
by karatestu
Mon Oct 22, 2018 1:34 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

1uf paper in oil any good for coupling caps ?
by karatestu
Sun Oct 21, 2018 6:11 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Hi Wolfgang, Thanks for your time with this. I only went with 10uf as that was what i had in there already -the naim stage had 2pairs of 10uf tantalum coupling caps - one pair straight after dac output and another pair after the bessel filter and before the output relay. I just kept the first pair o...
by karatestu
Sun Oct 21, 2018 5:49 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Nick wrote:
Sun Oct 21, 2018 2:29 pm
What 10uf cap are you using? They don;t all sound the same, maybe consider a film bipass?
Hi Nick,

10uf, 50v coupling caps are wima film ( mks 2xl)

Stu
by karatestu
Sun Oct 21, 2018 1:11 pm
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Hi again Wolfgang, I have been listening to the cdp without the output stage for a week already. I have 10uf coupling caps and 100k ohms to ground on the dacs output before the phono sockets. Also i left in a 680pf polystyrene cap which forms a low pass 1st order filter. It says in the datasheet tha...
by karatestu
Sat Oct 20, 2018 8:28 am
Forum: CD
Topic: CDP / DAC output stage
Replies: 27
Views: 2783

Re: CDP / DAC output stage

Hi wolfgang, Thanks for your input. Yes, i have read the data sheet again and it ties in with what i am hearing. Why Naim plonked a 7 pole bessel filter on the end i dont know. Or maybe i do. The unit has to measure well or it wont sell or be taken seriously. The data sheet says Zo (output impedance...