Just from a curiosity standpoint can you please mention more specific use conditions when you say this or that setting works best for you. Specifically, what are the intended load impedance and what is the actual load impedance, what is the supply voltage, what is the ball part speaker cable length, are the speaker cables twisted, shielded or just parallel and so on. Add as many or as few details as you like.
That's an awesome looking build, I really like that case and the price is right. Thanks for pointing it out.
To fix the hum, try grounding your input RCA ground to the chassis. Take the insulating washers off your RCA connectors if that's possible, or solder straps from the RCA connectors to a ring terminal bolted to the chassis.
Finally got my "Weiner" amp connected. I am using the same prototype chassis that I used with the DUG PBTL amp, so I connected my CineMag CMLI-15/15B input transformers to the amp. It's still too early to draw any conclusions as to how this amp compares to the other TPA31xx amps I've tried, especially the DUG PBTL amps. I will say this: this amp sounds very nice and smooth. Gmarsh did a fantastic job building this plug and play amp set up for 8 ohm nominal speaker loads. I can't wait to play with switching frequencies. I will also try this amp without the CineMags at the inputs, but I just had to give them a try, right?
In the photo, the second pair of DC power wires are insulated at the ends and tucked underneath the amp. The ground wires from the transformers are connected to the ground terminal next to the Standby terminal. There is absolutely no hum. I have to have my ear next to the midrange and tweeter horns of my efficient Klipsch Forte II speakers (8 ohms) to hear a very faint buzz that I cannot hear from my listening position.
Great job gmarsh.
In the photo, the second pair of DC power wires are insulated at the ends and tucked underneath the amp. The ground wires from the transformers are connected to the ground terminal next to the Standby terminal. There is absolutely no hum. I have to have my ear next to the midrange and tweeter horns of my efficient Klipsch Forte II speakers (8 ohms) to hear a very faint buzz that I cannot hear from my listening position.
Great job gmarsh.
The G-Wiener Stereo by far is the best 3116 bar none. However, like all the 3116 built in stereo, there is an inherit issue with the bass being bit flabby and thin. But PBTL design doesn't have the same bass issue, why I don't know. But having said that, the PBTL 3116 design such as the Dugg Mono blocks are still the heavy weight champion imo when it comes to having the "right stuff" when it comes to bass.
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I took delivery of my 2 weiners last Saturday. I did a quick smoke test to verify that both are working so I couldn't claim DOA later on. Both worked and I encountered the same Laptop hummm reported earlier and solved in previous posts. My brief listening test through a pair of Alpair 6M was very satisfying even though my aging, shotgun degraded ears are far from golden. That being said, I want to commend GMarsh, his girlfriend and dog for his leadership, engineering and manufacturing in this Group buy.
My initial design plan was to place both weiners in a box and implement switches to toggle each unit between Stereo and Mono configuration depending on speakers. Upon receiving the PCB, capacitors C37 and C39 prevent that implementation.
So my first question is, do I have to remove C37 and C39 to configure the MONO mode or could I merely raise them from the PCB to solder wires the the pads?
My second question that I have not seen answered, is, why is the design "fragile" when no output load is supplied? Is this because a more robust design would have compromised performance?
My initial design plan was to place both weiners in a box and implement switches to toggle each unit between Stereo and Mono configuration depending on speakers. Upon receiving the PCB, capacitors C37 and C39 prevent that implementation.
So my first question is, do I have to remove C37 and C39 to configure the MONO mode or could I merely raise them from the PCB to solder wires the the pads?
My second question that I have not seen answered, is, why is the design "fragile" when no output load is supplied? Is this because a more robust design would have compromised performance?
You can enable PBTL mode without removing C37/C39 by soldering wires to the bottom of the PCB. Jumper the "TPA facing" pins of C37/C39 to ground, pin 4 of the terminal block (the /SHDN pin closest to the LED connection) is probably your best bet.
I figured the majority of people wouldn't use PBTL, plus DUG makes a half decent PBTL board already, so I didn't put much thought into making the feature conveniently easy to use. I'll come up with something better for the next rev of the board.
The design is 'fragile' because without a load connected, the output filter basically becomes a series resonant LC circuit. If the input signal contains significant frequency content near that resonance, the LC could generate a high enough voltage to blow the output caps or burn up the EMI snubber resistors.
But honestly, you'd really have to try hard to make that happen. The resonance is at 41KHz on the 4 ohm amp, 61KHz on the 6 ohm and 60KHz on the 8 ohm. You won't get that out of a red book audio CD.
I figured the majority of people wouldn't use PBTL, plus DUG makes a half decent PBTL board already, so I didn't put much thought into making the feature conveniently easy to use. I'll come up with something better for the next rev of the board.
The design is 'fragile' because without a load connected, the output filter basically becomes a series resonant LC circuit. If the input signal contains significant frequency content near that resonance, the LC could generate a high enough voltage to blow the output caps or burn up the EMI snubber resistors.
But honestly, you'd really have to try hard to make that happen. The resonance is at 41KHz on the 4 ohm amp, 61KHz on the 6 ohm and 60KHz on the 8 ohm. You won't get that out of a red book audio CD.
Moved over to real speakers and had a bit of a shootout with a few power supplies. Feeding it with a Buffalo-II DAC + Amanero + Acko SO3 isolator/reclocker and using the ESS DAD digital volume control.
Sounding really great! So far the best PS is the 18V AMB sigma-11 (linear regulated). Dead quiet. The 24V Meanwell causes a bit of a buzz from the speaker, but I haven't tried the alternate grounding yet. Also got my first listen from my DUG amp.
Still waiting on a 20V Connexelectronic 300W SMPS.
Really digging this little Wiener!
BK
Sounding really great! So far the best PS is the 18V AMB sigma-11 (linear regulated). Dead quiet. The 24V Meanwell causes a bit of a buzz from the speaker, but I haven't tried the alternate grounding yet. Also got my first listen from my DUG amp.
Still waiting on a 20V Connexelectronic 300W SMPS.
Really digging this little Wiener!
BK
An externally hosted image should be here but it was not working when we last tested it.
Yesterday, I went to a buddy's house across the Bay to listen to a few amps including a couple TDA7297 Class AB chip amps and the Weiner amp. My friend has a pair of modified Klipsch Forte II's similar to mine. He has a DIY EF86 tube line stage he built at a class at the Randall Museum in San Francisco several years ago. The TDA7297 amps we tried sounded very good, but when we stuck the Weiner amp in my friend's system, he fell in love with it. It just sounded so refined, and he felt it was in par with his more expensive tube amps. With the Weiner, the sound quality was really engaging and we listened to many challenging tracks. To my ears, the bass response is every bit as good as what I remember hearing from the DUG PBTL amps. What's impressive is the midrange tonality and extended highs without any annoying brightness. Now a few of my friends want to know when the next group buy for the Weiner will take place.
In my own system, the Weiner sounds great. I just made a 1.5m pair of interconnects using Belden 8402 microphone cable and Switchcraft 3502AAU RCA connectors to connect my ARC LS7 line stage to the Weiner. I've been enjoying this setup so much, I haven't been too motivated to try the amp without the CineMag input transformers. I agree with eric777 that this is one of the best sounding TPA311x amps I've tried to date.
In my own system, the Weiner sounds great. I just made a 1.5m pair of interconnects using Belden 8402 microphone cable and Switchcraft 3502AAU RCA connectors to connect my ARC LS7 line stage to the Weiner. I've been enjoying this setup so much, I haven't been too motivated to try the amp without the CineMag input transformers. I agree with eric777 that this is one of the best sounding TPA311x amps I've tried to date.
Your mystery box is mostly together
I'll have it in the mail early next week.Your card was mailed out Apr.6, "4-6 weeks" is the delivery standard so we're still technically within that timeframe. Hopefully it'll be there soon...
Here are a few pics of my 'Wiener' under construction. Nothings really special, just integrating everything. Will have a power switch and volume control on the front. I'll also be using a 19v power brick rated at 4.5amps. Will share more when it's done.
Rick
Rick
Attachments
Thanks for mentioning that Gary. I've checked the continuity between the HS and all the nearby caps and TPs on the underside of the board. No shorts. There are a couple that are close to the HS, but they are not touching, so I should be okay. I haven't fired it up yet, but will check everything out before closing it up.
Rick