OK - thanks for that, I'll give it a (cautious) try.
Would lifting the input gnd be an option? I want to avoid adding coupling caps.
BK
Not really. Both the amp and the source will have some sort of "common ground". In theory if you run the amp off a 2-wire double-insulated power supply, and use something like a 9 volt battery to offset the amp ground from the DAC ground by 9 volts, that'll work in theory... but it doesn't seem right, and there might be some parastic current path (input bias current of the op-amps, perhaps) which charges that battery, so I can't really recommend that.
The op-amps are good for 36V rail to rail. One possibility would be to replace the DRQ74 inductor with a wound inductor of the same (primary) inductance that has more turns on the secondary side - this will maintain 12V on the positive rail, and you could set the negative rail to -15V or something.
To do this, I'd snag a Kool Mu or MPP toroid core from Magnetics Inc and some 24-26AWG magnet wire. They've got a design tool you can download from their website, use it to design a 10uH (maybe? I can't remember the value, I'll check it when I get home) inductor that can handle 1A of saturation current - this is your primary winding. Wind a secondary winding on there with 15/12 (approx) the number of turns as the primary.
Or haul the rectifier diode for the negative rail, and supply a negative analog voltage separately.
So my "full day of building amps" started about 9PM last night and concluded around 1AM, got SMT done on eight more stereo cards :/
What are people using as a preamp?
Hi. Just wondering, what are people using for a preamp with the wiener. I'm working on a project system and am having a really hard time finding a suitable preamp to make this a complete system.
Hi. Just wondering, what are people using for a preamp with the wiener. I'm working on a project system and am having a really hard time finding a suitable preamp to make this a complete system.
I should follow-up with more information...
What I want to do is create an integrated system that would have a 3118 amp chip (designed similar to the wiener) and also have a second board with volume control, input selector, usb reader, bluetooth receiver, Line-in, and FM tuner. I have seen and tried out many "mp3 decoder board" type devices from aliexpress with varying degrees of success. I had one board that was working quite well but it was the victim of a product revision that went sub-optimal; essentially turned this into this I'm hoping someone has had better luck than me and point the right direction.
What I want to do is create an integrated system that would have a 3118 amp chip (designed similar to the wiener) and also have a second board with volume control, input selector, usb reader, bluetooth receiver, Line-in, and FM tuner. I have seen and tried out many "mp3 decoder board" type devices from aliexpress with varying degrees of success. I had one board that was working quite well but it was the victim of a product revision that went sub-optimal; essentially turned this into this I'm hoping someone has had better luck than me and point the right direction.
Update: zero time. Haven't got anything done, too much life stuff going on, last couple times in the basement I did 12 boards worth of SMT and nothing else done, and that was over a week ago.
I'm committing as full of a day as I can tomorrow to the job. My home Linux server went down a couple nights ago, so I'm trying to get that back and going tonight.
Tigerfoo: all your stuff's built, gotta pack it up and get it out. Same with shochu (I think, I have to confirm). I'm banging out bare boards for ChuckT's order right now to build into full amps. After that it's patkwok, fjd, cft, ganaraska, fingerx, nickel, Chin Fai Chan, audioillness and jorem.
I've got all the parts, got everything I need to get this thing done, just life has an ugly habit of getting in the way. I'm so damn sorry for how this build went.
Next time around, given enough orders, I'll get boards built professionally built at a local board house. I'll probably have to get 50, maybe 100 orders to get the same sort of pricing since they'll gotta order large paste stencils, program machines, order parts on reels, etc.
I'm committing as full of a day as I can tomorrow to the job. My home Linux server went down a couple nights ago, so I'm trying to get that back and going tonight.
Tigerfoo: all your stuff's built, gotta pack it up and get it out. Same with shochu (I think, I have to confirm). I'm banging out bare boards for ChuckT's order right now to build into full amps. After that it's patkwok, fjd, cft, ganaraska, fingerx, nickel, Chin Fai Chan, audioillness and jorem.
I've got all the parts, got everything I need to get this thing done, just life has an ugly habit of getting in the way. I'm so damn sorry for how this build went.
Next time around, given enough orders, I'll get boards built professionally built at a local board house. I'll probably have to get 50, maybe 100 orders to get the same sort of pricing since they'll gotta order large paste stencils, program machines, order parts on reels, etc.
Hi gmarsh and other buddies,
Although a little bit late, wish you all Merry X'mas and Happy New Year!
Hope to receive the little wiener soon!
我從使用 Tapatalk 的 LG-H990 發送
Spent a 10 hour day at it today. Got all the mounting kits assembled, ten boards populated, of which three had PVCC shorts :/ I'm putting all damaged boards aside right now, building new boards instead and repairing once I can't build any more fresh boards.
Tigerfoo, shochu and patkwok are packaged and ready to mail out. Gotta bring one of the dogs to the vet tomorrow, I'll mail them when I'm out in town.
ChuckT's pile of boards now includes all 4 ohm and 6 ohm stereo cards. Eight fresh stereo boards just came out of the toaster oven, through-hole isn't done on them yet.
Other than the vet trip, I'll have most of tomorrow available to continue on it.
Tigerfoo, shochu and patkwok are packaged and ready to mail out. Gotta bring one of the dogs to the vet tomorrow, I'll mail them when I'm out in town.
ChuckT's pile of boards now includes all 4 ohm and 6 ohm stereo cards. Eight fresh stereo boards just came out of the toaster oven, through-hole isn't done on them yet.
Other than the vet trip, I'll have most of tomorrow available to continue on it.
Hi all,
I'm curious to hear from those lucky souls who have both the classic weiner amp and the new weiner pro.
I'm wondering if anyone has made direct comparison and if any preferences have been made? Thanks
Dave
I'm curious to hear from those lucky souls who have both the classic weiner amp and the new weiner pro.
I'm wondering if anyone has made direct comparison and if any preferences have been made? Thanks
Dave
I've built/listened to them all, and with my setups I definitely prefer the Pro. They are all great cards that make the most of the chip, but the Pro absolutely lives up to its name.
BK
Thanks for the reviews.
The Pro is definitely a better built amp. The audio input stage is way better, the TPA3250 chip has better specs and more output power capability, decoupling's better, and the output filter is deliciously overkill. Plus it has a bicolor LED that gives clip/temperature indication.
Whether it's a better *sounding* amp, I can't say.
The only thing that bugs me about the design in retrospect is the "plug in a through hole resistor" gain selection, I could have put gain selection jumpers or DIP switches on the card to make it easier. Would have added probably 5 bucks to the parts cost of the card and made it 5mm longer, but hey, that's the cost of 1 output inductor. I'll fix that in the next version.
Gmarsh, have you thought about implementing post-filter feedback on the next revision of the Pro?
Hi Gary,
Cheers for the holidays
I see your are enjoying your holidays doing what you do best, design and build circuits.
been busy this year for me, non electronics, building a garage/loft. Sort of lost track on the electronics.
Sorry I put my name down for a pro pcb and never came through for you. Hopefully I'll make good and get in on the next revision. Would like to test and measure it out like I did with the tpa3118 design.
Happy new year
Rick
Cheers for the holidays
I see your are enjoying your holidays doing what you do best, design and build circuits.
been busy this year for me, non electronics, building a garage/loft. Sort of lost track on the electronics.
Sorry I put my name down for a pro pcb and never came through for you. Hopefully I'll make good and get in on the next revision. Would like to test and measure it out like I did with the tpa3118 design.
Happy new year
Rick
Yep. I know people were experimenting with it on the class D forum on here, haven't kept up with that discussion but it looks like it makes a good improvement. You can add it on the existing Pro by adding 4 resistors to the card, unfortunately the layout doesn't make it an easy mod.
Question is, do I make it configurable, or put it there full-time?
Re: post filter feedback on Weiner Pro...
Is there any downside, or a reason why someone wouldn't want it? I suppose someone might prefer the sound without. But if it's just a matter of adding four resistors, then is it not implicitly configurable? I.e., just don't install those resistors if you don't want it. Having a switch or jumper for that particular feature seems unnecessary in my humble opinion.
Is there any downside, or a reason why someone wouldn't want it? I suppose someone might prefer the sound without. But if it's just a matter of adding four resistors, then is it not implicitly configurable? I.e., just don't install those resistors if you don't want it. Having a switch or jumper for that particular feature seems unnecessary in my humble opinion.
That is good to hear, I hope you had a nice holiday without worrying about the boards. 🙂