...Well i can make the motherboard...with shuntregs anyway.
as for the rest i'll get it working tonight again, last tests i did ..the bass sometimes was there...sometimes not.....rat's nest problems i guess.
Haven't heard it for some weeks.....been using a Sony CDP 337 ESD.....which made me wan't to go back to the drekling....the Sony does not have the focus of image that the drekling has.....go figure !
It's like looking at too pictures at same time ....instead of looking at one with both eyes ......
...although it does have that beautifull double TDA1541A sound.
as for the rest i'll get it working tonight again, last tests i did ..the bass sometimes was there...sometimes not.....rat's nest problems i guess.
Haven't heard it for some weeks.....been using a Sony CDP 337 ESD.....which made me wan't to go back to the drekling....the Sony does not have the focus of image that the drekling has.....go figure !
It's like looking at too pictures at same time ....instead of looking at one with both eyes ......
...although it does have that beautifull double TDA1541A sound.
Ok ZM,
As i told you on your home Forum....
This was not forgotten, not by a long shot.
But i do need to thank you for your patience and generosity, this will be properly finished now....and documented here.
I don't have nearly as much time as i wish i had for this and got myself into too many projects at once.
So i decided to prioritize and finish the Cheff/Pass UGS first and finish this after.
The Preamp is finished, as can be seen at the proper thread, now i spent the weekend going over this and making changes to the schematic according to your
last suggestions ( Post #146 ).
Finally on Sunday afternoon everything was ready and i switched on the music.....
As i told you on your home Forum....
This was not forgotten, not by a long shot.
But i do need to thank you for your patience and generosity, this will be properly finished now....and documented here.
I don't have nearly as much time as i wish i had for this and got myself into too many projects at once.
So i decided to prioritize and finish the Cheff/Pass UGS first and finish this after.
The Preamp is finished, as can be seen at the proper thread, now i spent the weekend going over this and making changes to the schematic according to your
last suggestions ( Post #146 ).
Finally on Sunday afternoon everything was ready and i switched on the music.....
Last edited:
1 - First of all i adjusted the voltage at each DAC current out put to 2.5V with the trimpots, no problem.
2 - verified the Shanling board and noticed that in my enthusiasm i had cut the DAC current ref resistor, so i reconnected it.
3- Verified that indeed that all old analog section was disconnected from DAC chip.
Listening tests:
Myself and my son ( his 22 year old ears are a precious help ) .
We both concluded that we had never heard such clear definition, detail and uncoloured topend.
Sound stage was amazing.
No tiredeness was aparent.
To be perfect there is only one detail to work on:
I was comparing this with the other input source i got: SONY CDP337 as transport with Buffalo24 DAC and the difference is that , while the Shanling has better definition, detailed sweet top end ( not tiring or metalic ), the lower bass energy is lower than on the Buffalo.
The bass is there but it lacks a bit of power compared to the buffalo.
I suppose that the lousy power wiring will contribute a little to this but i would welcome suggestions on how to correct this, once this is accomplished i can tell you without reservation that this will be an amazing player.....leagues better than the original " datasheet app note " analog section, better than the Buffalo ( which is saying a lot ) and better than the SONYs TDA1541A S2 DACS.
The reconnection of the DACs current REF made a big positive change ( .........!!! ) but this bass issue is still the weak point although by a much smaller margin now.
Voices are soooooooooooooooooo real !!!
Later today: proper documentation.
2 - verified the Shanling board and noticed that in my enthusiasm i had cut the DAC current ref resistor, so i reconnected it.
3- Verified that indeed that all old analog section was disconnected from DAC chip.
Listening tests:
Myself and my son ( his 22 year old ears are a precious help ) .
We both concluded that we had never heard such clear definition, detail and uncoloured topend.
Sound stage was amazing.
No tiredeness was aparent.
To be perfect there is only one detail to work on:
I was comparing this with the other input source i got: SONY CDP337 as transport with Buffalo24 DAC and the difference is that , while the Shanling has better definition, detailed sweet top end ( not tiring or metalic ), the lower bass energy is lower than on the Buffalo.
The bass is there but it lacks a bit of power compared to the buffalo.
I suppose that the lousy power wiring will contribute a little to this but i would welcome suggestions on how to correct this, once this is accomplished i can tell you without reservation that this will be an amazing player.....leagues better than the original " datasheet app note " analog section, better than the Buffalo ( which is saying a lot ) and better than the SONYs TDA1541A S2 DACS.
The reconnection of the DACs current REF made a big positive change ( .........!!! ) but this bass issue is still the weak point although by a much smaller margin now.
Voices are soooooooooooooooooo real !!!
Later today: proper documentation.
Last edited:
More tests
Hi again,
I figured out why the bass wasn't as deep as was expected,.....my BAD !
The V/I resistor ! ( R9 and R10 in the schematic ), the higher it is the better bass gets but is limited by the value of R1 and R2, if it is too high( above 1k8 ) then the pots can no longer adjust symmetric Dc out and uneven clipping occurs.
With the values shown sound is as described in previous post, fantastic.
The 47 Uf cap at the output is just for testing, will have to be optimized.
Further note: present circuit is easy to adjust to optimum values of 2,5 V on DAC Iout and center leg current to 1,2 mA ( these values are measured ! ).
Hi again,
I figured out why the bass wasn't as deep as was expected,.....my BAD !
The V/I resistor ! ( R9 and R10 in the schematic ), the higher it is the better bass gets but is limited by the value of R1 and R2, if it is too high( above 1k8 ) then the pots can no longer adjust symmetric Dc out and uneven clipping occurs.
With the values shown sound is as described in previous post, fantastic.
The 47 Uf cap at the output is just for testing, will have to be optimized.
Further note: present circuit is easy to adjust to optimum values of 2,5 V on DAC Iout and center leg current to 1,2 mA ( these values are measured ! ).
Attachments
Last edited:
RED Leds
During the weekend i decided to go over the alignement to see how stable it was nad to change the leds for matched sets, in this case red leds.
Since i had read somewhere that they can cause noise, i had done some searching on the web but came up emptyhanded....
The sound seemed a little cleaner after the change and realignement, but these are tiny details but since i'm finishing the PCBs i'd like to consider everything so i will not have to change them.
I did come across a coment that was supported by measurement, that bypassing the leds with 100U caps will lower LED noise and significantly improve PSRR....i would apreciate any input on this.
outstanding poits i would greatly apreciate input on as well are:
1 - output cap, which to use, right now i have 100u/25V ELNA.
2 - IV resistor, riken, Vishay dale ??? and more importantly 1k5 is recomended value ?
3 - bypass cap, right now is Wima FKP2 1nF.
Judging by my ears sound is very very good but if choosing the right components will improve it, obviously i'll do that....within reason
updated shematic:.....i haven't tested the LED bypass yet!
During the weekend i decided to go over the alignement to see how stable it was nad to change the leds for matched sets, in this case red leds.
Since i had read somewhere that they can cause noise, i had done some searching on the web but came up emptyhanded....
The sound seemed a little cleaner after the change and realignement, but these are tiny details but since i'm finishing the PCBs i'd like to consider everything so i will not have to change them.
I did come across a coment that was supported by measurement, that bypassing the leds with 100U caps will lower LED noise and significantly improve PSRR....i would apreciate any input on this.
outstanding poits i would greatly apreciate input on as well are:
1 - output cap, which to use, right now i have 100u/25V ELNA.
2 - IV resistor, riken, Vishay dale ??? and more importantly 1k5 is recomended value ?
3 - bypass cap, right now is Wima FKP2 1nF.
Judging by my ears sound is very very good but if choosing the right components will improve it, obviously i'll do that....within reason
updated shematic:.....i haven't tested the LED bypass yet!
Attachments
Last edited:
.......
outstanding poits i would greatly apreciate input on as well are:
1 - output cap, which to use, right now i have 100u/25V ELNA.
2 - IV resistor, riken, Vishay dale ??? and more importantly 1k5 is recomended value ?
3 - bypass cap, right now is Wima FKP2 1nF.
Judging by my ears sound is very very good but if choosing the right components will improve it, obviously i'll do that....within reason
updated shematic:.....i haven't tested the LED bypass yet!
1- use your own poison - Silmic ,BG ...... whatever ; you can always try to bypass it with 10n polycarbonate cap
2- same as (1) - some ppl prefer even plain Alen Bradley carbons .... I'm not loosing much of my sleep regarding issues like that one . 1K5 is just starting value ... I'm glad that you found influence on bass there ....
as long you can set proper DC voltage for DAC chip takeout points , any similar value is good .
3- polycarbonate is always my choice for speed ( wtf is that
) ; you can also try mica regarding LED bypass - let your ears decide do you need them or not ; just try ,then decide .
Thanks Zen Mod,
My ears tell me that i've never had better sound, i'm really happy with these thingies.
I was a bit surprised that i had to go all the way to 100uF for the output cap to get the Bass all in but the result is spectacular.
I'll try bypassing them with the 10nF caps you suggest and see what that does to the sound.
LEDs...if i remember well it seems that the LEDs will typically produce in the order of 40uV noise and bypassing them reduces that by +-10% but the impact on PSRR is much greater ( but then again i would suppose only if one has a really bad PS )... frankly i don't feel the need to try that as a priority, first i'll do the I/V resistor and output cap with bypass.
Thanks for the patience, from now on...only one project at a time...i like to finish them !
My ears tell me that i've never had better sound, i'm really happy with these thingies.
I was a bit surprised that i had to go all the way to 100uF for the output cap to get the Bass all in but the result is spectacular.
I'll try bypassing them with the 10nF caps you suggest and see what that does to the sound.
LEDs...if i remember well it seems that the LEDs will typically produce in the order of 40uV noise and bypassing them reduces that by +-10% but the impact on PSRR is much greater ( but then again i would suppose only if one has a really bad PS )... frankly i don't feel the need to try that as a priority, first i'll do the I/V resistor and output cap with bypass.
Thanks for the patience, from now on...only one project at a time...i like to finish them !
Here are pictures of actual state, i'd say finished ...yes, Motherboard and module PCBs...so i can do some more development later...hehe.
You can and should ask...i'll send them today after checking the boards for errors.
meanwhile...pictures:
Before you ask...the MBoard connects piggyback to original Shanling board through y wirewrap sockets...dificult to find but i got them.
You can and should ask...i'll send them today after checking the boards for errors.
meanwhile...pictures:
Before you ask...the MBoard connects piggyback to original Shanling board through y wirewrap sockets...dificult to find but i got them.
Attachments
Latest developments:
I had been wanting to try a little higher IV resistor, but knew i had to change the bottom resistor ( which was at 1K ) to be able to adjust the DC Voltage at the terminals of the IV resistor to +V/2...in this case 7.5V.
With IV resistor at 3k3...thinking that this should make life easier on the transistor delivering the current...since less is needed...
Bottom resistor is set at 100R.
All adjustments are made with no problem: DAC signal points are set at 2.5V and IV DC voltage at the mentioned 7.5V.
Listening:
Sound is indeed more relaxed...effortless, bass delivery in particular is amazing... powerful and well defined, voices seem even clearer and no harshness has crept in at the top end......simply gorgeous.
I hope some of you build this and compare notes with me, i would love a few more willing ears to sample the sound of this thingy and give me as impartial opinions as is possible.
Right now i'm going to enjoy the sound ......
I had been wanting to try a little higher IV resistor, but knew i had to change the bottom resistor ( which was at 1K ) to be able to adjust the DC Voltage at the terminals of the IV resistor to +V/2...in this case 7.5V.
With IV resistor at 3k3...thinking that this should make life easier on the transistor delivering the current...since less is needed...
Bottom resistor is set at 100R.
All adjustments are made with no problem: DAC signal points are set at 2.5V and IV DC voltage at the mentioned 7.5V.
Listening:
Sound is indeed more relaxed...effortless, bass delivery in particular is amazing... powerful and well defined, voices seem even clearer and no harshness has crept in at the top end......simply gorgeous.
I hope some of you build this and compare notes with me, i would love a few more willing ears to sample the sound of this thingy and give me as impartial opinions as is possible.
Right now i'm going to enjoy the sound ......
Polar or not
Hi guys, i have a question, right now i'm using Elna polar electrolitics as coupling caps and sound is as described, but should i switch to non-polar ?
if so i'm thinking 2 Silmic II in series ( 220u to make equivalent 110u ), which is close to the 100u i'm using now.
I'm choosing Silmic II because Nelson Pass has done extensive testing on them and has a very high opinion on their use in the signal path.
The other reason is that i like the sound i have at the moment so much......
Feedback would be greatly appreciated.
Hi guys, i have a question, right now i'm using Elna polar electrolitics as coupling caps and sound is as described, but should i switch to non-polar ?
if so i'm thinking 2 Silmic II in series ( 220u to make equivalent 110u ), which is close to the 100u i'm using now.
I'm choosing Silmic II because Nelson Pass has done extensive testing on them and has a very high opinion on their use in the signal path.
The other reason is that i like the sound i have at the moment so much......
Feedback would be greatly appreciated.
ZM,
You have email !
well - I didn't received it
whenever ..... try with >sasica5@gmail.com<
well - only your ears can decide that .....
either Silmic , or bip BGates in antiparallel connection ..... but choice must be yours
I hope that I will soon try some iteration of that I/V stage
first on some ancient Philips thingies , later on Primare CD31
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.