Hi picovolt,
Thanks for your reply. I already notice the spreadsheet in the first post but I was not sure if it is still usable or not.
This is my first approach to the headphones amplifiers. I just receive a Sennehiser HD 800 and I am looking for the appropriate ampli that can match. I see that many different solution are discussed and proposed. In my understanding the HD800 are SE, so the choice should be between the BAL-SE and the SE-SE depending on the available input from the source?
Sorry for the silly question, I try to go through the various threads but they are really very long ...
Thanks again and Regards,
Enrico
Hi picovolt,
Thanks for your reply. I already notice the spreadsheet in the first post but I was not sure if it is still usable or not.
This is my first approach to the headphones amplifiers. I just receive a Sennehiser HD 800 and I am looking for the appropriate ampli that can match. I see that many different solution are discussed and proposed. In my understanding the HD800 are SE, so the choice should be between the BAL-SE and the SE-SE depending on the available input from the source?
Sorry for the silly question, I try to go through the various threads but they are really very long ...
Thanks again and Regards,
Enrico
Hd800 come as SE, but if you change the cable they can be balanced. I don't have them, so don't have direct experience with this, but I'm willing to bet that they are better when run as balanced. You can build the bal-bal, and depending on how you wire it, run it as SE-bal, or bal-se, or bal-bal. If you use a balanced source, I'd recommend the fully balanced set up, with a cable that allows that.
Hi Enrico.., Nice to read you here too.., I have a couple of high-end headphones (Audeze LCD-3 and MrSpeakers Alpha Dog's) and have recabled them with long/short cables and various connectors and tails. The connectors for the HD 800 are available at several places too. There are some good tips in the DIY section over at Head-Fi.org - Headphone forums and reviews for audiophiles. I personnally love the sound of my diy balanced solid 0.5mm 4N silver in teflon sleeving and am thinking about some cotton sleeving next, much better then any of the oem cables. I also like to use the Neutrik XLR 4P male connectors instead of 6.35mm jacks (jacks always give a nasty spike, when you plug/unplug them accidentally, when the amp is still on) to use on my leads and a couple of tails, XLR 4P female to 3.5mm and 6.35mm jacks are easily made.
Hi stijn001
Thanks for your links and infos... actually I buy and received already the XLR cables for the HD800. I don't remember the brand now but I will check and let you know.
What I need now are the opc boards but the process is ongoing and I should receive them soon
Best Regards,
Enrico
He seems to be not responding to PMs and replies in this thread. But I see that he's quite active on the forum, so I don't understand the situation.
Hi Guys,
My apologies for the lack of response the past two weeks. I've been very busy with work and trying to get the final verification boards ordered.
The good news is that I will have 10 pieces of the brand new NTD1 circuit and PSU arriving this week! I will be building up one for myself for testing, and I will be looking for a few others to build the remaining 9 boards. Please let me know if you're interested. If all goes well with that, I will place the larger order and start shipping this new version. Expect the final NTD1 to start shipping in 2-3 weeks, and this is a firm date. It is currently my highest priority.
See attached some screenshots of the new layout.
Here are the key highlights:
- Vastly improved PSU using 4 x AD7142 HV regs. This is a dual regulated setup using an LM317 to fix the input voltage to the AD7142 which in turn will feed up to 39VDC output to the NTD1 with very low noise and high PSRR.
- Improved PSU layout using all SMD parts. Instead of using heatsinks, the entire board is now simply bolted to a heatsink using a thermal pad.
- The PSU is extremely flexible and could be used for any number of projects requiring higher output voltage.
- The new NTD1 board is also now all SMD, and heatsinks in the same manner as the PSU. The layout is much improved, and assembly will be much easier.
- The PCB now only includes mounting points for SMD polymer coupling caps. If people want to use massive film caps, they can be easily mounted off-board between the PCB and the XLR connector.
This version of the PCB will be offered as boards only, boards with key parts (eg, the ADI regs are very difficult to get!) and finally as a fully assembled and tested board! This will be my first time ever offering this, so it will be interesting to see how it goes!
More info to come soon, with pictures of the completed boards.
Here are a few other things I will be testing and posting about in the next few weeks:
1. A 100W@8R (200W@4R) bridged amplifier based around the OPA549 nested in the feedback loop of an LME49860.
2. Two additional NTD1 Variation boards (1 servo, 1 DC coupled)
3. DCX2496 output/input board (This is done, just needs to be published)
4. A 100W version of the LPUHP
5. A complete ADC based on the ESS ES9102 ADC. Good for pro recording or measurement systems
More updates to come later today and over the next week. Thanks to everyone for being patient, and my apologies again for all the delays.
Regards,
Owen
My apologies for the lack of response the past two weeks. I've been very busy with work and trying to get the final verification boards ordered.
The good news is that I will have 10 pieces of the brand new NTD1 circuit and PSU arriving this week! I will be building up one for myself for testing, and I will be looking for a few others to build the remaining 9 boards. Please let me know if you're interested. If all goes well with that, I will place the larger order and start shipping this new version. Expect the final NTD1 to start shipping in 2-3 weeks, and this is a firm date. It is currently my highest priority.
See attached some screenshots of the new layout.
Here are the key highlights:
- Vastly improved PSU using 4 x AD7142 HV regs. This is a dual regulated setup using an LM317 to fix the input voltage to the AD7142 which in turn will feed up to 39VDC output to the NTD1 with very low noise and high PSRR.
- Improved PSU layout using all SMD parts. Instead of using heatsinks, the entire board is now simply bolted to a heatsink using a thermal pad.
- The PSU is extremely flexible and could be used for any number of projects requiring higher output voltage.
- The new NTD1 board is also now all SMD, and heatsinks in the same manner as the PSU. The layout is much improved, and assembly will be much easier.
- The PCB now only includes mounting points for SMD polymer coupling caps. If people want to use massive film caps, they can be easily mounted off-board between the PCB and the XLR connector.
This version of the PCB will be offered as boards only, boards with key parts (eg, the ADI regs are very difficult to get!) and finally as a fully assembled and tested board! This will be my first time ever offering this, so it will be interesting to see how it goes!
More info to come soon, with pictures of the completed boards.
Here are a few other things I will be testing and posting about in the next few weeks:
1. A 100W@8R (200W@4R) bridged amplifier based around the OPA549 nested in the feedback loop of an LME49860.
2. Two additional NTD1 Variation boards (1 servo, 1 DC coupled)
3. DCX2496 output/input board (This is done, just needs to be published)
4. A 100W version of the LPUHP
5. A complete ADC based on the ESS ES9102 ADC. Good for pro recording or measurement systems
More updates to come later today and over the next week. Thanks to everyone for being patient, and my apologies again for all the delays.
Regards,
Owen
Attachments
Sorry, that should have read "ADP7142"
DAC and ADC are still progressing well. Everything was on hold for a little while to make time for a second little one
New boards for the ADC, DAC and controller are due to go out next week, but there's still lots of work on those to be done. Building prototypes is expensive and time consuming, so I've been doing it in spurts. Results from the V1 boards were extremely promising though, and V2 should be ready to share with everyone if all goes well.
Cheers,
Owen
DAC and ADC are still progressing well. Everything was on hold for a little while to make time for a second little one
New boards for the ADC, DAC and controller are due to go out next week, but there's still lots of work on those to be done. Building prototypes is expensive and time consuming, so I've been doing it in spurts. Results from the V1 boards were extremely promising though, and V2 should be ready to share with everyone if all goes well.
Cheers,
Owen