+ Reply to Thread
Page 1 of 28 12311 ... LastLast
Results 1 to 10 of 272

Thread: Collection of mods for Beresford TC-7520

  1. #1
    leo's Avatar
    leo is offline Circuit Junkie & DIY Room Forum Leader
    Join Date: Jan 2008

    Location: Notts UK

    Posts: 1,818

    Default Collection of mods for Beresford TC-7520

    Ok, thought I'd try and gather various mods etc for Stans TC-7520 dac and add them on here, if we could keep this as a mod thread only and keep the discussions on the other threads just so it makes things easier to find

    We'll start with the basics first, if I've done anything wrong or if its not clear just let us know, the idea here is to make things easy
    Other mods will be added later but for now

    Heres a pic of the riser board containing the op-amps



    Below with the THS4032 fitted for the fixed output and AD826 for the HA/variable
    For the THS4032 I used this browndog adaptor I converted to allow room with the 100nf ceramic fitted http://theartofsound.net/forum/showthread.php?t=2507



    Below with the LM4562 fitted for the fixed output, Stan recommded removing MLC5 / MLC6 ceramics if using this particular op-amp, I compared with and without and must agree I preferred it without those caps, you can easily compare ,either by cutting one side of the caps leg or carefully taking out the riser board and desoldering the caps altogether (watch out for the hot melt glue and double sided sticky pad )
    I've also not yet tested other op-amps with the caps removed, be careful with high bandwidth types



    Below with the metal can LM4562HA for the fixed output



    Op-amps I've tried so far in the fixed out which seem to behave

    OPA2132
    OPA2107
    AD826
    LM4562
    LM4562HA metal can
    Various NE5532
    THS4032 + 100nf bypass, I got best results soldering this cap directly onto the THS4032 pins rather than the socket pins, so far its behaving

    Only types I've tried so far for the variable out are OPA2107,AD826 and LM4562, all these worked, I personally like AD826 so far but its only early days

    Most op-amps can be found here http://uk.farnell.com/ and also Ebay

    Latest update 04/07/09

    Swapping PCM1716 to WM8716

    Warning, this is a fiddly job, not recommended if your not comfortable working with SMD, a mistake can result in a Knackered dac!
    My advice is wait for Stans SE version


    I used precision side cutters to cut the legs, I then removed each remaining leg on the pads with desolder wick
    As can be seen I managed to lift pad for pin12, luckily it wasn't connected to anything
    The board was cleaned with pcb cleaning fluid to remove caked on flux etc







    This mod made quite a noticeable difference to the sound, straight away I found it was smoother yet crisp in the highs
    Left to warm up dynamics increase nicely

    Added 05/09/99
    Results may vary with this mod depending on op-amp, system used etc
    Stans mod to the Caiman, details here http://theartofsound.net/forum/showthread.php?t=3740 also added a few pics and notes here for easy finding

    If original 100pf ceramics are still inplace these need to be removed and replaced with resistor (Stan found 36k to be best so far, I'd have to agree) and 100nf ceramic cap soldered in series
    Mod seems to work best with NA version of LM4562



    Fit as below



    Update 23/12/09

    Onboard 5v reg for dac and receiver changed to a diy discrete (this particular one in below pic is designed by John Swenson) I built it on vero/matrix
    Other possible replacements are what Stan uses, Mouser Part No: 580-7805SR-C Manufacturer Part No: 7805SR-C, theres also a 12v version which can be used for supplying the Caimans audioboard , you need to swap the main external psu though to one of Stans 15v Caiman upgrades to give the needed voltage drop for the regulator

    Alternative type regs are avaialble from Paul Hynes, Audiocom, Hi-fi upgrades etc, I hope to try a few of these others and do a mini shoot out, I'll add updates

    Signal capacitors on audioboard replaced with a set from Stan, some details here post 72 http://theartofsound.net/forum/showt...?t=4580&page=8

    I was quite pleased with these mods, both go well togther and help squeeze some more out of this unit




    Limks to useful posts updated 24/06/2010


    Stans mod to change the default input selection http://theartofsound.net/forum/showthread.php?p=131177
    Stans mod to increase gain http://theartofsound.net/forum/showp...&postcount=449
    Stans mod to shorten track from audioboard http://theartofsound.net/forum/showt...t=4580&page=49

    Values and locations for those wanting to cap roll on the main pcb around regulation, dac and receiver IC , Elna SilmicII seems to be the favourite choice from those who's tried them http://theartofsound.net/forum/showp...&postcount=457 http://theartofsound.net/forum/showp...postcount=1586

    List of part numbers for the caps , Thanks Fran (fmzip)

    Nichicon Muse Caps
    UES1C470MPM

    Elna Caps
    RFS-25v221 2pcs
    RFS-16V101 1pc
    RFS-16V100 8pcs

    Wima Cap
    MKS20-.068/63/10

    MartinT's diy external psu http://theartofsound.net/forum/showthread.php?t=6110
    Stans idea using a linear CB radio psu http://theartofsound.net/forum/showt...&highlight=psu

    Murata regs tried and recommended by Stan, thanks to fmzip for link
    http://parts.digikey.com/1/parts/159...-7805sr-c.html

    http://search.digikey.com/scripts/Dk...words=7812sr-c

    Dexa regulators tried and recommended by MartinT, thanks to Martin for link
    http://www.newclassd.com/index.php?page=34

    Updates 04/07/2010

    Stans mod for bypassing output stage op-amps
    http://theartofsound.net/forum/showt...411#post134411
    Last edited by leo; 04-07-2010 at 09:58.
    Cheers,
    Leo

  2. #2
    Join Date: Feb 2008

    Location: http://www.homehifi.co.uk

    Posts: 6,014

    Default

    The LM4562HA opamps with MLC5/MLC6 removed is a killer combination for string instruments and pianos. Triangles etc are also very well preserved during their travel from digital content to the ear drums.

  3. #3
    Join Date: Apr 2009

    Location: Sheffield

    Posts: 2,028
    I'm Confused.

    Default

    Hi Leo,
    Speaking personally (and I'm sure for many others also) I think this post is absolutely brilliant. There are almost as many upgrade options for the 7520 as there are owners or op-amps so drawing all the threads/options together in one place is great. I hope it permits a concensus of opinion to develop as to which are the optimum upgrades to go for. I know some members much prefer to form their own opinions about such things, but I'm also sure that others, like me, don't want to interfere in the bowels of their expensive 7520s any more than absolutely necessary, not having the knowledge or skill to recognise or correct any balls-up that they may commit.
    Just great !!
    DaveK.

    My System:
    Power: Belkin PF40, Custom.hifi.cables Hydra and DC PSUs.
    Sources: Self built HTPC with Xonar ST sound card, NAD T585 multi disc player, Sony BDP-S350, Squeezebox Touch, Techncs SL1210 (mod'd) + Nagaoka MP30, Thomson Sky HD box.
    Amps etc.: 2 x Mini-T amps, MF-X10D Valve buffer clone, StanDAC 7520/Caiman (mod'd).
    Speakers: Mission 774s with added super tweeters
    Cables: best I can afford and likely to change except Homar's RF attenuated co-ax's and Mark Grant USB and HDMI cables. I also like silver i/cs and speaker cable.

  4. #4
    leo's Avatar
    leo is offline Circuit Junkie & DIY Room Forum Leader
    Join Date: Jan 2008

    Location: Notts UK

    Posts: 1,818

    Default

    Thanks Dave! we can start off with the easy bits and probably go for the weird and wonderful mods later

    TBH I reckon just the simple op-amp changes is enough anyway for most
    Cheers,
    Leo

  5. #5
    Join Date: Feb 2008

    Location: http://www.homehifi.co.uk

    Posts: 6,014

    Default AKG K701 solution

    Anyone with a set of those cans know how hard it is to get decent bass out of them.
    If you are looking to improve that situation, then the THS4032 makes an ideal partner for the K701.

    Stan

  6. #6
    Join Date: Jun 2009

    Location: Yonkers, NY USA

    Posts: 165

    Default

    This write up and included pictures are fantastic. I feel much more confident when it comes time to install my LM4562

    Thank you much, Dave!
    David

    iTunes 7,PowerMac G4 733, Mac OS X 10.4.11, Airport Express, Beresford TC-7520 (Dual LM4562NAs) MLC5/6 clipped, 36K and 100nf cap mod, Behringer EP2000, Cambridge Soundworks Tower II

  7. #7
    Join Date: Jan 2009

    Location: Brisbane, Australia

    Posts: 77

    Default

    Leo I may be wrong, but regarding your pic of the riser board containing the op-amps, I was of the impression that the left op-amp was for fixed & variable output and the right op-amp for head-amp only?
    Granville

  8. #8
    Join Date: Feb 2008

    Location: http://www.homehifi.co.uk

    Posts: 6,014

    Default

    Quote Originally Posted by ReachtheSky View Post
    I was of the impression that the left op-amp was for fixed & variable output and the right op-amp for head-amp only?
    Granville
    Good call.

    STan

  9. #9
    leo's Avatar
    leo is offline Circuit Junkie & DIY Room Forum Leader
    Join Date: Jan 2008

    Location: Notts UK

    Posts: 1,818

    Default

    Quote Originally Posted by ReachtheSky View Post
    Leo I may be wrong, but regarding your pic of the riser board containing the op-amps, I was of the impression that the left op-amp was for fixed & variable output and the right op-amp for head-amp only?
    Granville
    Nice one! now changed ta
    Cheers,
    Leo

  10. #10
    Join Date: Nov 2008

    Location: NE Scotland

    Posts: 496
    I'm Jim.

    Default

    Great post Leo.
    Naim ND5 XS, nDAC, XP5 XS, 202, HC, NAPSC, 250.2, B&W 804s.
    AVR350, B&W HTM4, Gallo.
    Samsung, Oppo.

+ Reply to Thread
Page 1 of 28 12311 ... LastLast



 

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •