Most recent V3.6 Booster Boards are still available
Hey definitely buy Alex' amp! His soldering and assembly is some of the best I've ever seen.
I'm back, a bit anyway, after being too busy with the day stuff to even log on for several months. Day job keeps getting in the way of the audio hobby. I've been posting in the audio analyzer thread over in the equipment forum for a few weeks and someone let me know about the recent stuff here.
I do still have the most recent V3.6 O2 Booster Boards if anyone wants. Bare board + 26 awg silicon wire + connection pins is $15. Interesting that the connection pins alone are $3 of that. Fairly pricey Mill Max stuff, in a strip of 36 that I cut down, then only a 50% usabilty rate because the cutting exposes the pins from the carrier plastic on one side of the cut and can't be used.
I have one Booster Board right now with the two LME49600 chips and the two 0805 bandwidth control resistors (smaller SMD than the rest, next to the LME49600) soldered on for $39. Those are the 4 hardest parts to solder. The 49600s and their big tabs require a lot of soldering iron heat/wattage and a chisel tip to transfer it fast enough. The two resistors are smaller than the remaining 1206 sized (larger) parts. Both the bare board and the one with the chips are plus paypal fee and shipping. PM me if interested.
Two caveats though:
The BOM posted right now at the Google Drive link in the first post in this thread is a bit out of date. I spent about 2 hours on it yesterday have have it about 80% updated. That update should be posted out on Google Drive by tomorrow. I'm going to leave the existing, older, BOM there in a folder marked "older BOM", in case anyone is still assembling from that with parts bought last year. No values have changed, just parts out of stock and on order at Mouser and/or Digikey. For those I have alternates listed now in other brands.
The other thing is what I posted above in January (post #393), I still don't have any more recent audio analyzer tests of the Booster Board, past the initial set posted in this thread done with the QA401 analyzer. That is one of the reasons I'm spending time in the RTX6001 audio analyzer thread in the equipment forum, and a new software group buy for that unit going on, which allows auto-ranging. But no time frames on that, likely to be month(s) more before I can do an RTX6001 test on the Booster Board. I don't expect the results to be significantly different from the QA401 results though, just a slightly lower noise floor in the better analyzer, so kind of a moot point.
And...sorry but no fully assembled Booster Boards or Booster+O2. This is all DIY.
Have fun!
Hey definitely buy Alex' amp! His soldering and assembly is some of the best I've ever seen.
I'm back, a bit anyway, after being too busy with the day stuff to even log on for several months. Day job keeps getting in the way of the audio hobby.
I've been posting in the audio analyzer thread over in the equipment forum for a few weeks and someone let me know about the recent stuff here.I do still have the most recent V3.6 O2 Booster Boards if anyone wants. Bare board + 26 awg silicon wire + connection pins is $15. Interesting that the connection pins alone are $3 of that. Fairly pricey Mill Max stuff, in a strip of 36 that I cut down, then only a 50% usabilty rate because the cutting exposes the pins from the carrier plastic on one side of the cut and can't be used.
I have one Booster Board right now with the two LME49600 chips and the two 0805 bandwidth control resistors (smaller SMD than the rest, next to the LME49600) soldered on for $39. Those are the 4 hardest parts to solder. The 49600s and their big tabs require a lot of soldering iron heat/wattage and a chisel tip to transfer it fast enough. The two resistors are smaller than the remaining 1206 sized (larger) parts. Both the bare board and the one with the chips are plus paypal fee and shipping. PM me if interested.
Two caveats though:
The BOM posted right now at the Google Drive link in the first post in this thread is a bit out of date. I spent about 2 hours on it yesterday have have it about 80% updated. That update should be posted out on Google Drive by tomorrow. I'm going to leave the existing, older, BOM there in a folder marked "older BOM", in case anyone is still assembling from that with parts bought last year. No values have changed, just parts out of stock and on order at Mouser and/or Digikey. For those I have alternates listed now in other brands.
The other thing is what I posted above in January (post #393), I still don't have any more recent audio analyzer tests of the Booster Board, past the initial set posted in this thread done with the QA401 analyzer. That is one of the reasons I'm spending time in the RTX6001 audio analyzer thread in the equipment forum, and a new software group buy for that unit going on, which allows auto-ranging. But no time frames on that, likely to be month(s) more before I can do an RTX6001 test on the Booster Board. I don't expect the results to be significantly different from the QA401 results though, just a slightly lower noise floor in the better analyzer, so kind of a moot point.
And...sorry but no fully assembled Booster Boards or Booster+O2. This is all DIY.
Have fun!
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Thanks AGDR!
The booster board really helps make the O2 a better all around amp for headphones for sure. Several of my friends on other sites have these and like them very much.
The one I built works very, very well and its an improvement over the stock O2.
If I sell it thats great, but would like it to get to a home that uunderstands what this is all about and can appreciate it.
I am 69 yrs young, and thankfully can hear pretty well still at this age!! LOL!
But with 10+ amps, its not a loss here!! I rotate all my amps like one week of listening with one amp, then another and another and this way I can appreciate the qualities of them all...
All the best and thanks to AGDR for putting this one together....no on off thumps anymore!
Alex
The booster board really helps make the O2 a better all around amp for headphones for sure. Several of my friends on other sites have these and like them very much.
The one I built works very, very well and its an improvement over the stock O2.
If I sell it thats great, but would like it to get to a home that uunderstands what this is all about and can appreciate it.
I am 69 yrs young, and thankfully can hear pretty well still at this age!! LOL!
But with 10+ amps, its not a loss here!! I rotate all my amps like one week of listening with one amp, then another and another and this way I can appreciate the qualities of them all...
All the best and thanks to AGDR for putting this one together....no on off thumps anymore!
Alex
New V3.6 BOM posted
Took a few more days than I expected, but a new V 3.6 BOM is posted now out at the project Google Drive folder in the first post in this thread. I've left the previous BOM available in an "older version" folder.
Direct link: Booster Board V3.6 BOM
Several parts were out of stock and on order at Mouser and Digikey. I've now added alternates. Everything in the BOM (with those alternates) should now be in-stock, as far as I know. If anyone finds any problem parts that I've missed, please post or PM!
Alex - thanks!
Took a few more days than I expected, but a new V 3.6 BOM is posted now out at the project Google Drive folder in the first post in this thread. I've left the previous BOM available in an "older version" folder.
Direct link: Booster Board V3.6 BOM
Several parts were out of stock and on order at Mouser and Digikey. I've now added alternates. Everything in the BOM (with those alternates) should now be in-stock, as far as I know. If anyone finds any problem parts that I've missed, please post or PM!
Alex - thanks!
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Useful xlsx file. All information are included there!Took a few more days than I expected, but a new V 3.6 BOM is posted now out at the project Google Drive folder in the first post in this thread. I've left the previous BOM available in an "older version" folder.
Direct link: Booster Board V3.6 BOM
Several parts were out of stock and on order at Mouser and Digikey. I've now added alternates. Everything in the BOM (with those alternates) should now be in-stock, as far as I know. If anyone finds any problem parts that I've missed, please post or PM!
Alex - thanks!
V3.6 BOM revised again and posted
Thanks! And that V3.6 BOM just got even better. I was just looking at it and realized that while I had gone all through the Mouser and Digikey columns I had forgotten to update the Farnell UK column. I've now updated the Farnell column and in the process added a Newark column, since those two companies are related (Farnell in the EU, Newark here in the USA). Same direct link as above in post #405.
Thanks! And that V3.6 BOM just got even better.
I was just looking at it and realized that while I had gone all through the Mouser and Digikey columns I had forgotten to update the Farnell UK column. I've now updated the Farnell column and in the process added a Newark column, since those two companies are related (Farnell in the EU, Newark here in the USA). Same direct link as above in post #405.
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Thanks to CHiroshi, I have a booster board on the way!!!
I'm excited about taking advantage of the extra power and I'm thinking about doing the 15Vrms mod along with relocating voltage regulators to the backplate for heatsinking. The heatsinking mod is discussed in agdr's o2 mod thread.
He mentions that the bypass/decoupling capacitors & diode should be mounted directly to the regulators. I've attached the diagram I believe he refers to. I have basic soldering skills, but I dont know enough about electronics to know which caps to order from digikey. agdr says that he uses MLCC caps,but the schematic shows two polarized caps and two non polarized caps.
Are there specific caps that I should be using? After I do this mod are there any components on the o2 that need to be shorted or removed?
I'm excited about taking advantage of the extra power and I'm thinking about doing the 15Vrms mod along with relocating voltage regulators to the backplate for heatsinking. The heatsinking mod is discussed in agdr's o2 mod thread.
He mentions that the bypass/decoupling capacitors & diode should be mounted directly to the regulators. I've attached the diagram I believe he refers to. I have basic soldering skills, but I dont know enough about electronics to know which caps to order from digikey. agdr says that he uses MLCC caps,but the schematic shows two polarized caps and two non polarized caps.
Are there specific caps that I should be using? After I do this mod are there any components on the o2 that need to be shorted or removed?
Attachments
I am undoing a mod agdr did on my O2- I am reverting back to the original gain structure (reverting R7,R3,R14, R20, C12 and C11 back to the original values, thereby removing voltage divider I had agdr install). Will end up with 1x and 3x which should work well with my source and headphones (45Ω Ety ER4XR and 250Ω Beyer Amiron. Also replacing the pwr supply filter caps per the recommendation on his website.
I am hoping to do this without removing the Booster Board. Since I don't need battery power, I will remove the two battery terminals closest to the edge of the board to gain access. I'm hoping this will give me sufficient access to remove R19 and R23 (which fortunately were socketed when the original mods were done.
My concern is that I may have to get the booster board out of the way completely to insert the gain set R's and I'm wondering how to safely do that if necessary. Can the white wire there be soldered to another terminal (I think that wire will reach the terminal on the right)?
Wish agdr was still around. My eyes ain't what they used to be and this is a densely packed PCB so I am depending on a helping hands/magnifier to get this done. Pwr supply filter caps are easy to get at out in the open but the parts under the boosterboard could get tricky. Any advice or tips welcome.
I am hoping to do this without removing the Booster Board. Since I don't need battery power, I will remove the two battery terminals closest to the edge of the board to gain access. I'm hoping this will give me sufficient access to remove R19 and R23 (which fortunately were socketed when the original mods were done.
My concern is that I may have to get the booster board out of the way completely to insert the gain set R's and I'm wondering how to safely do that if necessary. Can the white wire there be soldered to another terminal (I think that wire will reach the terminal on the right)?
Wish agdr was still around. My eyes ain't what they used to be and this is a densely packed PCB so I am depending on a helping hands/magnifier to get this done. Pwr supply filter caps are easy to get at out in the open but the parts under the boosterboard could get tricky. Any advice or tips welcome.
Attachments
