Jump to content

mwl168

High Rollers
  • Posts

    1,363
  • Joined

  • Last visited

  • Days Won

    1

Everything posted by mwl168

  1. Two 24v secondaries will work just fine for the desired 20VDC regulated output. You can go down to 20v since the GR's drop out voltage is quite low. That information is in the thread somewhere. To power the balanced Dynalo you'll need plenty of current so I would recommend at least 1.2A for each secondary and make sure you have enough heatsinks for the pass transistors.
  2. If you can post a photo of good resolution of the faulty board it will help spot if something looks suspicious.
  3. Also, double check the current limit resistor is the correct value. Last time I experienced similar problem it was due to the current limiting resistor being 1000 times the correct value (5.1K vs. 5.1R).
  4. I have a later version of the 009 and have used it with HV, Carbon, BH and SRX Plus. I have not purposely compared the pairings in a systematic way, mostly I just enjoy listening to the music. I do like the combo of the 009 with the SRX Plus a lot!
  5. Has anyone built a 15K attenuator BOM that you are willing to share? Thanks!
  6. Thanks Craig! Very interesting history. I had to look up what "dyslexic" means. And after reading the information, it makes me wonder if that's the problem I have
  7. I actually remember the Lynx brand - probably back in the 90's. The dealer I worked with (and I trust his taste for good sounding audio gears) carried it. One of my cousins may have purchased one with his recommendation IIRC. It has not combusted to my knowledge :-)
  8. One thing to consider if you have not already is to elevate the resistors and diodes slightly off the board by 3mm or so. It's a practice used by many (myself included) to prevent leakage or arcing due to the high voltage involved in this amp.
  9. Tried again tonight without the servo engaged. Similar result - offset shot up to about 170 VDC a couple of seconds after power off. Will try leaving the LV supply on and see what happens as JoaMat suggested next - need to rig something up to separate the HV and LV power switches.
  10. Will do. It may be a while before I get around to it - have been working on resolving a noisy I2S connection problem for the past month.
  11. Was listening to my Carbon/009 tonight and before I shut it down I measured the offset. I have the opto servo engaged and the offset was hovering under 1 VDC while the amp is on. Upon shutting down the power, within a second or two, the offset shot up to just under 200 VDC and gradually declined from there. I plan to disable the opto servo and when I do that I will measure the offset again and report back.
  12. To my knowledge, the GB boards I ordered from PCBNet are either made in the US or Taiwan, most likely Taiwan. I did get a few PCBs from China (Seeed Studio and all 1.6mm and 2oz copper IIRC) and the quality is reasonable to me. But once I experienced the PCBNet quality, it was hard to go back. To the point and in all fairness, I also got one shitty batch of PCBs from a Taiwan factory who I would never do business with again.
  13. I am fairly certain I've measured similar effect of my Carbon which I have been listening to on and off for months without issue. I do disconnect my headphone before power on and off.
  14. Yes, you should see 2 test points next to each of the two 50 ohm resistors on each channel.
  15. Never built the Transcendentsound amp but they have been around for a long time. AFAIK, they are OTL amps. I did build a pair of OTL mono blocks. One thing the true OTL power amps I know of have in common is that they don't like low impedance loads. So I am guessing your speakers' impedance will be a big factor how well the amp will work.
  16. Were the resistance measured with the resistors on the PCB or off the PCB?
  17. Ah, I read your message all wrong - was thinking down the other direction. I am devoted to keeping the overkill spirit alive... Will report back my findings if and when I try it. I looked up the TPS7A4700, indeed many layouts available at eBay and quite a few talks over at DIYAUDIO about using it to replace the Trident regulator for Buffalo DAC. It's rated at 1A max current out so will need to do one-per-channel if I do decide to go this route. Thanks all again for your help!
  18. Thanks Kevin. Do you have some concern about using the GRLV for digital? To be specific, I am thinking about the possibility of using the GRLV to power the ESS9018 based Buffalo II DAC and potentially the USB receiver/reclocker/isolator too. I am expanding my Buffalo II DAC to dual mono setup and add the Amanero/Hermes/Cronus USB-to-I2S receiver. Between the 3 they may draw as much as 1.2A current. Speaking of that, really looking forward to your multi-bit DAC.
  19. I have a question about the voltage setting; if I want to configure the GRLV to output, say, 5.5VDC. Is it as simple as using a LT1021-5 5V voltage reference and change the R7 and R8 resistors to arrive at the 5.5VDC output? My plan is to use the positive half of the GRLV to power the digital section of my DAC.
  20. Did you try check things step by step? First check the transformer is working properly without connecting to the power supply. Then check the power supply without connecting to the amp boards and see it outputs correct voltages?
  21. Oh, I guess I should have been more specific. I subconsciously separate my ES phones (007 and 009) from the dynamic phones in two different camps and don't compare them side by side. In absolute terms, my 009 and 007 setup is hands down better in every way. No comparison in my personal opinion.
  22. I've run my Carbon with and without the opto servo. Without the servo, the Carbon is very stable and quickly settles as everyone is saying. With that said, the opto servo does work very well and is effective almost as soon as the amp is powered on.
  23. Listening to the SS Dynalo and HD650 combo for the past few weeks, I certainly would not associate the term "veil" with the HD650. The friend that I built the SS Dynalo for texted me this morning and independently arrived at the same impression. What impresses me about the SS Dynalo is that it somehow manages to sound more revealing and warmer at the same time (compared to the already great original Dynalo). It also gives the HD650 bass extension I previously did not know was possible. I wonder how much can be attributed to Kevin's wonderful GoldenReference PS. Never heard the TH900. Only listened to the HD800 very briefly in an uncontrolled environment (2011 Annual DIY event at SF), its bright treble left me a scar that has not quite healed. Listened to Nelson Pass's "The Beast" driving his DIY Lowther at the same event. That's something very special!
×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.