Go Back   Home > Forums > Source & Line > Digital Source

Digital Source Digital Players and Recorders: CD , SACD , Tape, Memory Card, etc.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 12th August 2005, 09:52 AM   #61
diyAudio Member
 
Join Date: Jun 2004
Location: Italy
Hello Fin:

Thanks for the schematics.

I have seen the complex circuit to which you make reference and I think is remarkable to have been planned in 1989/90.

I want to realize all the modifications necessary to make play well it.
1) To separate to the feedings with others two transformers,
2) Bypass the filter of the SAA7220 connecting directly word, clock and date, from the SAA7210 to the TDA1541 and to activate the Mute ones connecting pin the 23 delSAA7220 with pin the 11 of the SAA7210,
3) To replace the clock from the PC74HCU04P (z206),
4) To replace the clock of the TDA1541
5) To replace the electrolytyc capacitors
6) To replace the two operational NE5534
7) Bypass the adjustable analogic output.
Is there other to make?
I will be happy of all the councils that you will give to me.
Ciao
Giovanni
  Reply With Quote
Old 15th August 2005, 05:46 AM   #62
Fin is offline Fin
diyAudio Member
 
Fin's Avatar
 
Join Date: Dec 2003
Location: -
Quote:
Originally posted by supertrioe
Hello Fin:

Thanks for the schematics.

I have seen the complex circuit to which you make reference and I think is remarkable to have been planned in 1989/90.
Yes - it appears that they did quite a good job but, according to the digital experts, there are a few simple changes that will make a big improvement to this circuit. You can also go a lot further, as I intend to, and make some significant changes.

The most important and simplest of these is to disconnect and disable the SPDIF signal going through the flip-flop which also reclocks BCK (Z207), and disable the relevant inverer in Z206.


Quote:
1) To separate to the feedings with others two transformers,
I don't think there is space for any more transformers - but I plan to replace the analogue Tx with a larger torroid - 25VA.


Quote:
2) Bypass the filter of the SAA7220 connecting directly word, clock and date, from the SAA7210 to the TDA1541 and to activate the Mute ones connecting pin the 23 delSAA7220 with pin the 11 of the SAA7210,
I will leave mine as an oversampler initially - to hear the best that this can offer.


Quote:
3) To replace the clock from the PC74HCU04P (z206),
4) To replace the clock of the TDA1541
You can feed a new clock into the existing distribution - but you will still be using more than one inverter in the 74HCU04 - which is not optimal. I plan to use a Tent XO2 - which has three outputs - to replace the 74HUO4 completely. This will clock BCK (Z207), the filter and the decoder directly.


Quote:
5) To replace the electrolytyc capacitors
What will you use?


Quote:
6) To replace the two operational NE5534
OPA627??


Quote:
7) Bypass the adjustable analogic output.
There is a small white board which can be removed. There are probably some other components to remove - but I haven't looked too closely yet.


Quote:
Is there other to make?
There is always more...................................


Quote:
I will be happy of all the councils that you will give to me.
Looks like we might be able to help each other as we go.


Please note that I haven't tried any of this yet - but I have recieved some excellent help from very knowledgable members of this forum.
__________________
Regards
Fin
  Reply With Quote
Old 24th April 2007, 02:45 AM   #63
Fin is offline Fin
diyAudio Member
 
Fin's Avatar
 
Join Date: Dec 2003
Location: -
Default Reclocked Delta

Quote:
Originally posted by Fin
Has anyone tried converting a Delta 70.2 to Non Oversampling?

The filter is in a socket so it would be easily reversible.

Quote:
Originally posted by simon dart
I have, it's very easy.

The word clock, bit clock and data are terminated by a resistor right by the DAC. I just lifted the ends of the resistors and soldered the min coax onto them and then back to the filter board, so it's easliy reversable for comparison. Do a search for pin info.

I didn't make any changes to the filtering. Subjectively, the music became slightly more "organic" however I can't honestly say it made a huge difference.


Non - Oversamplig

That is indeed the easiest way to convert this CD player to non-oversampling.....however, it also disables the reclocking of the Bit Clock. This might be one of the reasons why it didn't make a huge difference. The benefits of reduced jitter by going non-oversampling were possibly negated by the loss of the reclocking.

To retain the reclock - you need to connect the Bit Clock output fron the decoder to the reclocking flip-flop (pin 2 of Z207).


Ultimate Reclocking???

I've been thinking a lot about an even better way to install a new clock in this CD player and it seems that is is possible to do it in such a way as to reclock all of the signal lines going to the DAC.

My proposed method requires the use of a clock with multiple outputs and a 1/2 clock output. A TentLabs XO2.5 is a ready made solution or you can build your own clock devider.

The first thing to do is remove the old clock including the hex inverter Z206. Z206 can then be replaced with a 74HC74. One half of this dual flip-flop could then be disabled.

Next - disconnect all signals going through Z207 (74HC74) and also disable one half of this dual flip-flop.

Then - redirect WS to pin 2 (D) of Z207 and connect pin 5 of Z207 (Q) to R221 (which connects to pin 1 of the TDA1541A. Likewise - redirect DATA to pin 2 of the newly replaced Z206 (D) and connect pin 5 (Q) to R222 which connects to pin 3 of TDA1541A.

Then install the new clock. Connect the 1/2 clock output (5.6MHz) to R223. This will provide direct clocking of TDA1541. Connect one clock output to pin 3 (CK) of Z206. Connect another output to pin 3 (CK) of Z207. These will now work as reclockers for WS and DATA. Connect the final clock output to pin 11 of SAA7220.

All of this is just thoery at this stage and it would be great if someone with experience of clock distribution could have a look and comment
__________________
Regards
Fin
  Reply With Quote
Old 27th April 2007, 12:32 AM   #64
Fin is offline Fin
diyAudio Member
 
Fin's Avatar
 
Join Date: Dec 2003
Location: -
I suppose a diagram would help for those who do not have the service manual:-
Attached Files
File Type: pdf arcam delta 70.2 audio board.pdf (83.0 KB, 98 views)
__________________
Regards
Fin
  Reply With Quote
Old 27th April 2007, 12:38 AM   #65
Fin is offline Fin
diyAudio Member
 
Fin's Avatar
 
Join Date: Dec 2003
Location: -
And maybe a picture of the are in question too:-
Attached Images
File Type: jpg arcam delta 70.2 - dac pcb.jpg (58.0 KB, 266 views)
__________________
Regards
Fin
  Reply With Quote
Old 27th April 2007, 06:46 PM   #66
diyAudio Member
 
Join Date: Dec 2001
Location: Eindhoven
Quote:
Originally posted by Fin
I suppose a diagram would help for those who do not have the service manual:-

oh, great, another HC04 based oscillator. Even worse, they use another inverter from that same package to buffer the SPDIF output - yuck.........
__________________
Guido Tent
www.Tentlabs.com
  Reply With Quote
Old 28th April 2007, 04:25 AM   #67
Fin is offline Fin
diyAudio Member
 
Fin's Avatar
 
Join Date: Dec 2003
Location: -
Quote:
Originally posted by Guido Tent

oh, great, another HC04 based oscillator. Even worse, they use another inverter from that same package to buffer the SPDIF output - yuck.........

Then I assume that there is no downside to the proposed strategy in post #63 above.

My only concern is that I have overlooked something that will make this idea unworkable or that I will have to do additional major surgery to the pcb in order to make it work. I don't really want to butcher this nice CD player. So, if it looks like there might be a problem, then I would rather go with the simpler approach as outline by Jean-Paul at the beginning of this thread.
__________________
Regards
Fin
  Reply With Quote
Old 15th June 2007, 03:40 AM   #68
Fin is offline Fin
diyAudio Member
 
Fin's Avatar
 
Join Date: Dec 2003
Location: -
Quote:
Originally posted by Guido Tent
oh, great, another HC04 based oscillator. Even worse, they use another inverter from that same package to buffer the SPDIF output - yuck.........

......and a shared 74HC74 dual flip-flop to reclock the bitclock and the SPDIF. Can it get any worse?

This is why I want to re-do the whole thing and use a Tent XO2/5 instead. I'm quite happy that the proposed direct 1/2 clocking of the DAC along with re-clocking of WS and Data is correct............BUT I still need to find out about those series resistors.

The existing series resistors in the BCK, WS and Data lines are 390 ohms just before the DAC chip. If I use direct 1/2 clocking for the DAC - should I remove the 390 ohm resistor in the BCK line and just use the 47 ohm resistor that is already on the Tent XO2/5 board?
__________________
Regards
Fin
  Reply With Quote
Old 14th April 2008, 09:21 PM   #69
tubenut is offline tubenut  South Africa
diyAudio Member
 
tubenut's Avatar
 
Join Date: Nov 2002
Location: South Africa, Jhb
Quote:
Originally posted by jean-paul
BTW the upper power transformer often hums mechanically. It stops humming when you remove the tie wraps. The cable connecting it to the analog board is too long, you can shorten it a few cm at the power pcb side.

Quote:
Originally posted by jean-paul
Just do it

Farguar suggested to replace the transformer but I found it to be quiet when the tie wraps are removed. Nice when you're on a budget but replacing them is better. Problem is that the pinout is non-standard so replacing it for a standard type is unconvenient. Reason that I don't like that transformer is that it hums and that it becomes too warm IMO.

I have ended up with a D170.
Fitted my own clock proto type first. Now gutted the Arcam Digital output board out and fiteed an old Theta output board (gets reclockked as well, came from an old Data 1, the modified LD).
Sounds miles better then the Arcam PCB IMO.

I cut the tie wraps on the trafo.

However, after taking the unit round to a friend to listen to it it developed a really nasty mechanical buzz on the PSU board.
I tried DC blockers, amended the 220 vs 240 V scheme no avail. Then, while holding and twisting the board a little tryng to mechanically damp the buzz it stopped.
It really seems as if these two transformers are exciting eachother.
I have ended up with a rubber bumpon squezed between the two trafos, buzz gone!. So as not to rip the smaller black trafos pins out, I solder sucked all its connections and then resoldered it, it now sits slighly skew. There is no tension. It really just seemed like I managed to move them out of eachothers magnetic field.

Thought this may be of interest.

May post a pic later.
__________________
Guillaume
Croak Audio Exploration
  Reply With Quote
Old 24th February 2011, 02:35 PM   #70
apm is offline apm  Bulgaria
diyAudio Member
 
Join Date: Jan 2008
Hi guys,
i want a schematic, please! my mail is : atanas_mil4ev@abv.bg
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Arcam Delta 70/70.2 FibCouple Digital Source 2 12th January 2008 11:42 PM
Delta 290 Arcam mike salway Solid State 0 17th September 2005 03:03 PM
Arcam Delta 70.2 Rotellian Digital Source 2 16th January 2004 10:33 PM


New To Site? Need Help?

All times are GMT. The time now is 05:46 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2