Power transformer and enclosure arrived. I have just installed missing parts and everything is working. But I am concerned about one thing, during turning off I measure 1.9V DC transient at output with nothing connected, and about 500mV with junk test earphones. After spike, it is slowly falling. When amp is working everything is fine, DC offset is under 1mV. Same with no source connected. It should be like that, and is it safe to connect my Beyers?
Q&A Time!
You bet! The amplifiers are completely done, tested, and ready to go. The hold up is me saving up enough money to do a production run of about 50 units.
The website is also in the works, so it's just a matter to timing everything and doing an official release.
It is getting very close now though.
The ES9018 is used for the DAC itself. Some of the details are in the first post of this thread.
That transient sounds quite high compared to what I've seen on my unit. It's not going to be an issue for larger Beyer phones, but it seems to imply there is an issue somewhere.
A few questions:
1. Are you using the correct "PSU V2" and the suggested output caps and output voltage?
2. Is this with a source connected or with the input floating?
3. How are you measuring this? Scope? DMM?
4. The load on the output shouldn't really have much impact on the startup or shutdown transient, so I'm curious about why it went from 1.9V down to 500mV with a load.
5. Is it swinging positive or negative?
6. Is it the same every time?
Regards,
Owen
You bet! The amplifiers are completely done, tested, and ready to go. The hold up is me saving up enough money to do a production run of about 50 units.
The website is also in the works, so it's just a matter to timing everything and doing an official release.
It is getting very close now though.
The ES9018 is used for the DAC itself. Some of the details are in the first post of this thread.
That transient sounds quite high compared to what I've seen on my unit. It's not going to be an issue for larger Beyer phones, but it seems to imply there is an issue somewhere.
A few questions:
1. Are you using the correct "PSU V2" and the suggested output caps and output voltage?
2. Is this with a source connected or with the input floating?
3. How are you measuring this? Scope? DMM?
4. The load on the output shouldn't really have much impact on the startup or shutdown transient, so I'm curious about why it went from 1.9V down to 500mV with a load.
5. Is it swinging positive or negative?
6. Is it the same every time?
Regards,
Owen
1. PSU V2, parts as suggested earlier in thread. Output voltage is standard 15V, reading 14.98V / -15.11V
2. Nothing connected to RCA sockets.
3. Cheap ~10 USD DMM
5. Negative
6. Tested several times a minute ago, 830mV and about 150mV with phones then slowly falling so it looks much better now. Powering on of course brings 1mV immediately. I don't know why it vary so much from last result.
If it relevant, i'm using 100k Alps pot, as suggested changed R14&R18 to 1M Ohms and shorted R13&R17. Tommorow i will check second kit which i had assembled.
2. Nothing connected to RCA sockets.
3. Cheap ~10 USD DMM
5. Negative
6. Tested several times a minute ago, 830mV and about 150mV with phones then slowly falling so it looks much better now. Powering on of course brings 1mV immediately. I don't know why it vary so much from last result.
If it relevant, i'm using 100k Alps pot, as suggested changed R14&R18 to 1M Ohms and shorted R13&R17. Tommorow i will check second kit which i had assembled.
Assembled second unit today, this is without pot and i have same problem like in first one - rather large DC at output during powering off. Seems like it is changing. Sometimes it is 1.9V, sometime it can be 600mV but values usualy look similar. What can be wrong?
Hi Owen,
I received my PCBs 2 days ago, very nice and I love the white mask.
Where can I get the latest BoM for The Wire SE-SE and PSU for the latest PCBs?
Thanks
Do
I received my PCBs 2 days ago, very nice and I love the white mask.
Where can I get the latest BoM for The Wire SE-SE and PSU for the latest PCBs?
Thanks
Do
Sorry to report this, I'm having the same problem with the PSU v2 and SE-SE amp on shutdown. PSU v2 built as per BOM, input/output caps are 2700uF not 3300uF versions of the correct Nichicon caps.
SE-SE has been used for roughly 18 months with PSU v1. Built V2 last night, double checked everything and wired into place this morning... Measured with a DMM.
PSU v2 first power up ... not connected to SE-SE; ~ +/-15.2Vdc ... on switch off the rails appear to stay high for a long time before dropping [larger caps & no load?].
PSU v2 connected to SE-SE, No output load & no input source connected; Power on and running, DC offset is <1mV ... Shutdown DC offset on both channels spike at -2.4 to -1.6 Vdc, but stay >200mV for ~10 seconds.
PSU v2 power down connected as above ... Rails drop from +/-15V after ~ 1 second. Negative rail settles at ~ -1.5Vdc & Positive rail settles at ~ -0.5Vdc.
With 22R 7Watt dummy load ... power down DC offset spikes at ~ 1Vdc and drops to <10mV in <5 seconds.
With 180R 3Watt dummy load ... power down DC offset spikes at ~ 1.7Vdc and drops to <10mV in <5 seconds.
Paul.
SE-SE has been used for roughly 18 months with PSU v1. Built V2 last night, double checked everything and wired into place this morning... Measured with a DMM.
PSU v2 first power up ... not connected to SE-SE; ~ +/-15.2Vdc ... on switch off the rails appear to stay high for a long time before dropping [larger caps & no load?].
PSU v2 connected to SE-SE, No output load & no input source connected; Power on and running, DC offset is <1mV ... Shutdown DC offset on both channels spike at -2.4 to -1.6 Vdc, but stay >200mV for ~10 seconds.
PSU v2 power down connected as above ... Rails drop from +/-15V after ~ 1 second. Negative rail settles at ~ -1.5Vdc & Positive rail settles at ~ -0.5Vdc.
With 22R 7Watt dummy load ... power down DC offset spikes at ~ 1Vdc and drops to <10mV in <5 seconds.
With 180R 3Watt dummy load ... power down DC offset spikes at ~ 1.7Vdc and drops to <10mV in <5 seconds.
Paul.
Hi Paul,
Thanks for the thorough evaluation! I was wondering if the strange behavior was a result of the cheap DMM BamboszeK was using as they can sometimes give strange results when measuring a transient.
I will look into this on Monday and get a few scope captures to see what's going on. This obviously isn't desirable behavior but given the relatively low loaded voltage and short duration, it's still certainly safe to use them as is for now.
I'll characterize what's going on and see if there's a way to remedy it. The solution might be as simple as either smaller or asymmetrical output filter caps on the PSU.
Cheers,
Owen
Thanks for the thorough evaluation! I was wondering if the strange behavior was a result of the cheap DMM BamboszeK was using as they can sometimes give strange results when measuring a transient.
I will look into this on Monday and get a few scope captures to see what's going on. This obviously isn't desirable behavior but given the relatively low loaded voltage and short duration, it's still certainly safe to use them as is for now.
I'll characterize what's going on and see if there's a way to remedy it. The solution might be as simple as either smaller or asymmetrical output filter caps on the PSU.
Cheers,
Owen
Thans for reply. Actually as you said it is not a big deal for bigger headphones, but with IEMs pop sounds a bit dangerous 🙂
I'm using exactly these caps: EKZH250ELL272MK35S United Chemi-Con | Mouser
I'm using exactly these caps: EKZH250ELL272MK35S United Chemi-Con | Mouser
Thanks Owen 🙂 I'm going take some macro photo's of the board, see if I can spot anything and make doubly shore everything is wired correctly.
I have some of the Nichicon 330uf 16V caps handy. I might give those a go on the output side, see if they help any.
Paul
I have some of the Nichicon 330uf 16V caps handy. I might give those a go on the output side, see if they help any.
Paul
Couldn't find any anomalies and took a chance on plugin-in the Senn HD-650s... There is a 'Tick' on power up and 'Pshhh...' on powering down, but not at a level I'd consider damaging to the phones. So full speed ahead.
Thanks for all the time and effort your putting into this Owen, very much appreciated 🙂
Pic's 1-3; getting ready to build the PSUs. Needed to bend the legs of the regs myself, and just about to fit the new PSU...
Very hard to comment on what changes occurred [if any] on swapping PSUs, maybe a touch cleaner through the bass registers. Without a direct A/B comparison it's a very tough call...
Paul
Thanks for all the time and effort your putting into this Owen, very much appreciated 🙂
Pic's 1-3; getting ready to build the PSUs. Needed to bend the legs of the regs myself, and just about to fit the new PSU...
Very hard to comment on what changes occurred [if any] on swapping PSUs, maybe a touch cleaner through the bass registers. Without a direct A/B comparison it's a very tough call...
Paul
Attachments
I guess my question got ignored... Would be nice if the latest BoM was always on the first post of its respective thread.
Thanks
Do
First post has been updated with all information.
All it takes is a 5 second search for "BOM" by user "opc"
Regards,
Owen
All it takes is a 5 second search for "BOM" by user "opc"
Regards,
Owen
Forgot to add the picture of the fully wired SE-SE with new PSU and a few extras... not my tidiest build but works a treat.
Totally amazed by the clarity of detail and overall performance of this setup, certainly not left wanting for sure... However, am intrigued to find out how the BAL-BAL and a better DAC sound 🙂
Totally amazed by the clarity of detail and overall performance of this setup, certainly not left wanting for sure... However, am intrigued to find out how the BAL-BAL and a better DAC sound 🙂
Attachments
Here is my one - The Wire by BamboszeK - Imgur
First I wanted to use a potentiometer, but later I abandoned that idea and i'm using volume control at DAC 😛
First I wanted to use a potentiometer, but later I abandoned that idea and i'm using volume control at DAC 😛
You guys have this chassis thing down to an art!
Both builds look great, and really follow the minimalist intentions of the The Wire.
The layouts are excellent, and the finished product looks very professional!
Kudos to both of you 🙂
Regards,
Owen
Both builds look great, and really follow the minimalist intentions of the The Wire.
The layouts are excellent, and the finished product looks very professional!
Kudos to both of you 🙂
Regards,
Owen
Thanks Owen 🙂
Bamboszek: very nice build 🙂 Something to try out with the ODAC... put a clip-on ferrite ring on the USB lead a couple of inches away from the ODAC USB port and see if you notice an improvement in detail.
Paul
Bamboszek: very nice build 🙂 Something to try out with the ODAC... put a clip-on ferrite ring on the USB lead a couple of inches away from the ODAC USB port and see if you notice an improvement in detail.
Paul