Thanks Rhing. If I understand correctly then your arrangement will maximise power transfer from primary to secondary of your transformer. Subsequently half of that power would then be dissipated by the resistor. Conversely what I ended up doing will mean a less efficient transfer of signal power by the transformer. But the TPA3116 will perhaps see a higher signal voltage (thinking of transformer output impedance and amp input impedance as a voltage divider) which should help to minimize interference/disortion. And no power is dissipated by a resistor.
I am just trying to wrap my fuzzy head around what is going on here and whether it is worth me trying to reverse what I have done and try it your way. I agree absolutely that listening is the important test for what works best!
DUG-1 Group Buy Dual PBTL Monoblocks
I just got my new amp PCB from Dug today! 😀 Looks fantastic - appears to have all the needed mods and options (bootstrap snubbers, separated pin 17 analog supply, turn on pop suppression delay, and most importantly - lots of room for a fat flat-wire Coilcraft inductor). Nicely done Dug - thanks!
100 watts/ch into 2ohms in stereo 😎
I just got my new amp PCB from Dug today! 😀 Looks fantastic - appears to have all the needed mods and options (bootstrap snubbers, separated pin 17 analog supply, turn on pop suppression delay, and most importantly - lots of room for a fat flat-wire Coilcraft inductor). Nicely done Dug - thanks!
100 watts/ch into 2ohms in stereo 😎
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I just got my new amp PCB from Dug today! 😀 Looks fantastic - appears to have all the needed mods and options (bootstrap snubbers, separated pin 17 analog supply, turn on pop suppression delay, and most importantly - lots of room for a fat flat-wire Coilcraft inductor). Nicely done Dug - thanks!
100 watts/ch into 2ohms in stereo 😎
Better warm up the soldering iron! Just finished building and now listening to my 2nd DUG mono pair.
Boards are a pleasure to work on after moding the Chinese boards.
ChrisMmm,
Where is the BOM? I still need to order the SMT's and a new microtip and solder for the iron. It will be a while before I get one built. I am busy building my Trynergy (tractrix fullrange synergy) right now so have my hands full. Your build looks awesome by the way. How does it sound compared to a full up modded YJ blue/black?
Where is the BOM? I still need to order the SMT's and a new microtip and solder for the iron. It will be a while before I get one built. I am busy building my Trynergy (tractrix fullrange synergy) right now so have my hands full. Your build looks awesome by the way. How does it sound compared to a full up modded YJ blue/black?
I see DUG just posted a new BOM on the PCB thread, I used an older one in the thread.
I have yet to do a direct comparison. Unfortunately things change in my system frequently and I wouldn't rely on my memory of how the YJ sounded. Will set up a proper comparison when I get the DUGs installed in cases.
Just from initial listening I would say they are all the fully modded YJ is tho the PSU I am using with the DUG is a new one for me.
Output snubbers at the red YJ board
Hi
I have the old YJ red board.
The output snubbers consist of 4.7 R and 10 n . I notice the datasheet suggest 331 capacitors and 10 R.
Is this value usable and serves its purpose ?
Secondly the output snubbers is placed after the inductor and before the speaker terminal . Is this location ok ?
thks
kp93300
Hi
I have the old YJ red board.
The output snubbers consist of 4.7 R and 10 n . I notice the datasheet suggest 331 capacitors and 10 R.
Is this value usable and serves its purpose ?
Secondly the output snubbers is placed after the inductor and before the speaker terminal . Is this location ok ?
thks
kp93300
IIRC, I believe you mentioned that your YJBlue with the CineMag xformers has no turn on/off pop. Did it before you setup the trannies? Somehow I got the (possibly wrong) impression that the input transformers are a way to help prevent the turn on/off pops.
Anyway, sounds like you're not alone with the Sure tpa3116 on/off pops. Mine does too. My Sure tpa3116 turn off pop is about the median across all the 3116 boards I've yet played with. But the turn on thump is by far the worst!
On the other hand, my Sure tpa3110 has no turn-on pop, and about average turn-off pop (which I fixed with a manual shutdown switch). The only mod I've done to the Sure tpa3110 is to replace all the DC caps with the OSCONs. This is definitely my favorite amp so far.
Here is mine modded board:
and snubber mod 😉
An externally hosted image should be here but it was not working when we last tested it.
and snubber mod 😉
An externally hosted image should be here but it was not working when we last tested it.
Matt, Are you talking about the new Sure 2X15 W TPA 3110 or the original 2X8 W? If it's the new 2X15 W board, did you replace all 8 caps with the OSCON's ?
Sorry, I wasn't clear! Yes, indeed, I'm talking about the newer 2x15W board.
And yes again, I did replace all eight caps. (I spent more on replacement caps than the board itself!) I realize that increases capacitance about 50%, from stock of 4x220=880uF to 4x330uF=1320uF (per side).
I either didn't bother to listen before replacing the caps, or did so briefly that I can't remember what the difference was. 🙂 Either way, I'm quite happy with this setup. (Doesn't mean I'm going to stop tinkering with these boards though!)
The YJ amp before mods had a very faint turn-off pop (really almost a click). When I tried a pair of 3.3uF/160V Wima MKP10 film caps on the inputs, the pop became more audible. With the CineMag CMLI-15/15B input transformers, there is no turn-on noise at all. The faint turn-off pop that was there before is almost inaudible.
I still have my original Sure TPA3110 amp with no output LC filter, just Ferrite beads, and this amp does not have any turn-on or turn-off noises. This amp is very quiet too, not like the Sure TPA3116 amp. Based on my positive experience with the Sure TPA3110, I had high expectations for the TPA3116 amp.
At this point, I am more inclined to try DUG's DIY TPA3116 amps in master/slave PBTL mode since the CoilCraft SER2915L-103KL inductors fit nicely on the board, and it looks to be well designed electronically and mechanically.
On a separate note, Roger Modjeski of Music Reference will be speaking to a group from the San Francisco Audiophile Society. He is going to present a seminar on amplification. Roger is also launching an audio engineering school in Berkeley, CA. A few of my friends and I are attending the talk tomorrow. If you've never heard a Music Reference tube amplifier, you owe it to yourself to audition one.
Im curious to know what the SN ratio is on the modded YJ and the Sure amps. I wonder if there above 100 and beyond.
OK, just did my SMSL TPA3118 amp's mods, 2x 330uf Panasonic OSCONS and 8x 470uF Panasonic FMs.
While the clarity and dynamics have opened up a bit, I really get the sense that the pace or tempo of the music has quickened, it feels too fast... am I going crazy? Should I get some rest instead of modding this?
While the clarity and dynamics have opened up a bit, I really get the sense that the pace or tempo of the music has quickened, it feels too fast... am I going crazy? Should I get some rest instead of modding this?
These are old Sowter 4069 transformers.
Sound much better than my stock SMSL 36a PRO with 3118 😉
It's interesting to read about poor performance of Sure amp. It has all those nice little features implemented and still sounding bad? 🙁 My understanding is that, apart from pop transistors and output diode rectifiers, the board is as datasheet suggests.
It could be bad PCB layout, but my bet is that those rectifying diodes are not helping the issue. So replacing those diodes with straight wire could help or then there might be something else that is not right. 😉 Either way I'm very interested to hear, if someone manages to solve issues related to Sure board.
It could be bad PCB layout, but my bet is that those rectifying diodes are not helping the issue. So replacing those diodes with straight wire could help or then there might be something else that is not right. 😉 Either way I'm very interested to hear, if someone manages to solve issues related to Sure board.
I don't know, still some 20 parts more then datasheet if you deduct some like above. Replacing output diodes with wire would bring DCinput straight to speakers, so you mean other diodes I guess?