It's a good idea to measure the voltage across R10,11,12, and 13 to get an idea of the currents flowing through the diamond buffer.
Driver current V(R10)/R(R10), output current V(R12)/R(R12).
Rev 2.0 is set up for 10 mA in the driver, 25 mA in the output. Rev 1.4s (14s) ran about 30 mA in the driver and 20 mA in the output, with the original BOM values. Your current values should give you 20 mA in the driver, and probably 5-10 mA in the output but I'm not sure so you best check that last number. While its up to you I think it best to keep the bias current from dropping too low.
/R
Driver current V(R10)/R(R10), output current V(R12)/R(R12).
Rev 2.0 is set up for 10 mA in the driver, 25 mA in the output. Rev 1.4s (14s) ran about 30 mA in the driver and 20 mA in the output, with the original BOM values. Your current values should give you 20 mA in the driver, and probably 5-10 mA in the output but I'm not sure so you best check that last number. While its up to you I think it best to keep the bias current from dropping too low.
/R
You measure the voltage "across" the resistor, with one lead at one end of the resistor, one lead at the other. A positive voltage denotes current "from" the red lead to the black, a negative voltage denotes current in the other direction. Divide the measured voltage by the known resistance to find the current.
This isn't a knock at you Lance, but generally: people should know this. I mean, before they ever pick up a soldering iron they should know Ohms Law and understand how to use a DMM...
This isn't a knock at you Lance, but generally: people should know this. I mean, before they ever pick up a soldering iron they should know Ohms Law and understand how to use a DMM...
not at all dig away. i know i should make an effort. every time i go looking for information people start blabbing on about formulas so i just give in. i dont know how i managed to get a BSc in networking with Cisco certs as well as an introduction to embedded computer systems when the balcksmithing panned out but i did.. lol
now i live a life of leisure
now i live a life of leisure
not to bad for a nights work. made up with completely standard BOM apart from the Rike caps.
they look pretty good with the Rike Audio S-Caps.
now just to go and plug them in and see if they blow up
they look pretty good with the Rike Audio S-Caps.
now just to go and plug them in and see if they blow up
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
i'ts alive
initial impressions are impressive. things are fresh so cant give a full response but they sound a tad more open than the 14s1 boards but not as 'heavy'.
i think your mains power must be really bad Richard or you have a lot of garbage floating around in the air as these sound clean as a whistle but i do have very good clean mains power. sound a looot better than the standard 14s1 boards from the off.
i'll play with the zobel and the by-pass caps but at the moment things sound darn good.
Lance
initial impressions are impressive. things are fresh so cant give a full response but they sound a tad more open than the 14s1 boards but not as 'heavy'.
i think your mains power must be really bad Richard or you have a lot of garbage floating around in the air as these sound clean as a whistle but i do have very good clean mains power. sound a looot better than the standard 14s1 boards from the off.
i'll play with the zobel and the by-pass caps but at the moment things sound darn good.
Lance
Leave it powered up for at least 48 before making any assessment. Personally I think it takes a few weeks, especially if your coupling cap is new out of the bag.
I had a problem with my last 2.0 build, my latest set of boards run far quieter even with no mains earth. I'm using higher quality resistors (PRP/Takman) this time, but that's about the only thing that has changed. I think the noise previously was related to wear hardening on the input wires, which had cause one to crack and develop a very poor contact. (That's the occupational downside of solid core chassis wiring...)
I had a problem with my last 2.0 build, my latest set of boards run far quieter even with no mains earth. I'm using higher quality resistors (PRP/Takman) this time, but that's about the only thing that has changed. I think the noise previously was related to wear hardening on the input wires, which had cause one to crack and develop a very poor contact. (That's the occupational downside of solid core chassis wiring...)
i used stranded cat5 as i have ermm well rather a lot of it.
coupling caps are from other boards so well bedded in. i have been up since i turned the new boards on and cant stop listening to try and find anything and i have only found one bit of harshness but i'm pretty sure that it's in the recording. the new 20 boards are stunning and make my 14 boards sound closed in. if they sound like this now i can't wait to hear them in a week or so once everything is well settled. superb, simply superb.
coupling caps are from other boards so well bedded in. i have been up since i turned the new boards on and cant stop listening to try and find anything and i have only found one bit of harshness but i'm pretty sure that it's in the recording. the new 20 boards are stunning and make my 14 boards sound closed in. if they sound like this now i can't wait to hear them in a week or so once everything is well settled. superb, simply superb.
you are in for a treat
i have only tried 3 types of caps. it was easy for me to tell the difference between the caps that i have tried as i have 2 x 14s boards configured the same and the boards have connectors for quick removal/install.
the standard caps that Richard sends out are open but a bit rough in the vocals and get confused when things get a bit hot in the recording. but nice none the less.
Mundorf MCap EVO Oil Aluminium (0.68uf), very nice vocals and fairly open but like the standard caps they can sound a bit rough and congested. they take forever to bed in.
Rike Audio S-Caps PIO (0.68uf), do everything right. open, spacious, clean, deep dark blackness. if i were to criticise them then i would say that they can be too revealing but they never loose control no matter how hot the recording gets, you get what's there. they take less time than the EVO to bed in but still take a good 100hrs+. worth the money i paid for them.. yes as i got them brand new of the bay at half price, worth full retail.. hhhmm subjective, if you dont want to worry about the caps making a difference then yes i would say they are worth the retail price.
what i really wanted was Intertechnik Audyn True Copper Caps but the company never got back to me with the proper sizes as there are conflicting sizes depending on what web site you went to. but i think they are big. it was the diameter i was worried about but i have changed plans so that does not matter any more, i might try them out at a later date.
i'll pop the EVO oil in the 20 boards just to see how good they are against the Rike's and report back as the evo oil are 1/5 of the price.
When the cost of a pair of capacitors cost the same as the rest of the BOM combined though, I think people should step back and reconsider the value proposition on offer.
At least as an investment it is transferable. I mean, if you buy a set you can use them in any number of future projects if you decommission or downgrade the original.
And Lance has it basically right: the kit polypro caps are chosen simply for "not sucking", there is considerable tuning/improvement to be found by changing for other brands/types. As for how much you want to pay for that, everyone has their threshold.
I use Multicaps. I've also heard many positive reviews of the Obbligatos. Neither are crazy-expensive. The Multicaps are clean and fast, maybe bright. The Obbligatos the opposite: warm and dark, maybe sticky.
At least as an investment it is transferable. I mean, if you buy a set you can use them in any number of future projects if you decommission or downgrade the original.
And Lance has it basically right: the kit polypro caps are chosen simply for "not sucking", there is considerable tuning/improvement to be found by changing for other brands/types. As for how much you want to pay for that, everyone has their threshold.
I use Multicaps. I've also heard many positive reviews of the Obbligatos. Neither are crazy-expensive. The Multicaps are clean and fast, maybe bright. The Obbligatos the opposite: warm and dark, maybe sticky.
On the improvement of the R2.0 boards:
Well, I mean yes I can point to a specific reason for the improvement: the bias currents have dramatically changed from 30 mA / 20 mA (driver/output) to 10 mA / 25 mA. It makes the diamond buffer stage easier for the op amp to drive. There's no other changes on the same level: the filter capacitance increases 50%, the trace layout of the diamond buffer is re-worked. Neither are big deals.
Thing is I can't make a connection between this one major change between the revisions and the overall improvement in noise floor and sound quality generally. So I'm just going to run with it...
Well, I mean yes I can point to a specific reason for the improvement: the bias currents have dramatically changed from 30 mA / 20 mA (driver/output) to 10 mA / 25 mA. It makes the diamond buffer stage easier for the op amp to drive. There's no other changes on the same level: the filter capacitance increases 50%, the trace layout of the diamond buffer is re-worked. Neither are big deals.
Thing is I can't make a connection between this one major change between the revisions and the overall improvement in noise floor and sound quality generally. So I'm just going to run with it...
Bibio kindly gave the Mouser parts for some pins in an earlier post.
I have found the following at the local store which does the trick nicely. They are sold as "logic-level check terminals" rather than standoffs.
I have found the following at the local store which does the trick nicely. They are sold as "logic-level check terminals" rather than standoffs.
Attachments
i have mucked about with pins and sockets for the caps but TBH i ended up just using a solder sucker to remove the solder then using the iron to pull the legs out one at a time. as long as you get the solder completely melting it's not a problem. i do use 'hackle pliers' to grip the legs of the caps, this also has the added benefit of being a heat shunt.
the holes are that large i have not had any problems with ripping out the 'bungs'.
i did have an idea to use the pins out of 'scotch lock' connectors as dry connections so you would just push the leg into the V but never got round to it.
the holes are that large i have not had any problems with ripping out the 'bungs'.
i did have an idea to use the pins out of 'scotch lock' connectors as dry connections so you would just push the leg into the V but never got round to it.