probably need few decades of terrible conditions to get to 470uF
This was my hunch, too. My linear supply will quickly dive to the point of Weiner shutoff at loud volumes and heavy bass, if my post-rectification tank capacitance is 3,300uF (for example). However, with a 30,000 uF tank cap, I can run the amp as loud as my speakers can reasonably handle without any interruptions. The Weiner likes a sturdy, steady flow.
Yes do improve your powersupply, it makes a difference. When price is no object try the Mascot, ask what options/versions they offer and select the most reliable for this application. And also try your Wiener on passive sub only, that tripped protection here too.
It isn't the 470's or the Oscons, Dugs with 330uF don't have bass tripping protection, not when using one ampboard per powersupply, not when using 4 ampboards per powersupply. Hiamp minis with 220uF one or two per supply do not trip protection on bass, chinese unmodded ac1308 using original two chinese 470uFs do not trip protection on bass, with japanese electrolytics they don't either. Not on Mascot, not on Meanwell, not on 15V, not on 16V not on 21V not on 24V, not even with 26+V 500W Connexion PSU they trip protection on bass peaks. it doesn't happen, but the Wiener did and now it doesn't anymore.
It isn't the 470's or the Oscons, Dugs with 330uF don't have bass tripping protection, not when using one ampboard per powersupply, not when using 4 ampboards per powersupply. Hiamp minis with 220uF one or two per supply do not trip protection on bass, chinese unmodded ac1308 using original two chinese 470uFs do not trip protection on bass, with japanese electrolytics they don't either. Not on Mascot, not on Meanwell, not on 15V, not on 16V not on 21V not on 24V, not even with 26+V 500W Connexion PSU they trip protection on bass peaks. it doesn't happen, but the Wiener did and now it doesn't anymore.
Yeah - the point of the decoupling on the Wiener is to make sure that the PVCC rail has a very low impedance at audio frequencies and beyond, so that the TPA's loop gain is doing audio duty instead of PSRR duty.
I can't really put huge caps on there because most switching power supplies aren't happy with huge amounts of capacitance on their outputs, as it interferes with their control loop and can even make them go unstable. Besides, most switchers have a fast enough transient response to maintain a stable output voltage.
With a linear supply, you'll want a big cap as you describe, or better yet a regulated output.
I'll be honest, I've only ever run the amplifier off switching supplies or batteries. My test bench power supply is a Mean Well RS-150-24, and I've used a 12V SLA also.
<4.5V is impossible I would think, because it happened on sub only too, it is more likely that high frequencies get into 3118, powersupply's or cdplayers's, that might, given the huge peaking 3118 outputfilter when only bass/sub is connected, also cause currents for inaudible frequencies. Higher capacity is in filterless classD datasheets and application notes too, to limit emision/radiation, I remember some 15 watt Zetec advise 2 times 1000uF for FCC reasons. It is strange, but setup is different from how ampboard and PSU and sources are placed whenever I tried any ampboard. Stranger would be two medical grade regulated fast psu's dropping below 4.5V imo.
I got a 15V Meanwell to compare befor ordering more Mascots. Limits were closerby with the Meanwell, tpachips run warmer, idle too. But that temperature difference was powering 2 Dugs at one powersupply, 8800uF, Meanwell might not handle the capacity very well. Listening comparisons also included the two low capacity Hiamps pbtl's, listening that made no difference from 8800uF Dugs for Meanwell, less powerfull and detailed bass and more quickly distorted highs on climax in music. Higher capacity electrolytics, the Dugs always outperformed the Hiamps in bass, PSU's, strugling with capacity or not, the psu bass differences were smaller, both PSU's being around 150W if specs are comparable.
Initial checking Wiener was on easier speakers and 24V MeanWell, 24V isn't option with these harder speakers, for separate bass it is an option, but I kept voltages close with four pbtl's
I got a 15V Meanwell to compare befor ordering more Mascots. Limits were closerby with the Meanwell, tpachips run warmer, idle too. But that temperature difference was powering 2 Dugs at one powersupply, 8800uF, Meanwell might not handle the capacity very well. Listening comparisons also included the two low capacity Hiamps pbtl's, listening that made no difference from 8800uF Dugs for Meanwell, less powerfull and detailed bass and more quickly distorted highs on climax in music. Higher capacity electrolytics, the Dugs always outperformed the Hiamps in bass, PSU's, strugling with capacity or not, the psu bass differences were smaller, both PSU's being around 150W if specs are comparable.
Initial checking Wiener was on easier speakers and 24V MeanWell, 24V isn't option with these harder speakers, for separate bass it is an option, but I kept voltages close with four pbtl's
Glancing at the Wiener code, low DC protection happens at 3/4 of the PVCC value measured when the TPA is taken out of shutdown, or say 18V if you're running off a 24V supply. PVCC is checked at a ~100Hz rate to ensure it doesn't go below this value.
The AVR has a clean/regulated power supply, PVCC sense going into the AVR is filtered, and the AVR is sitting on the low current half of the board, so I doubt there's any conversion error.
That's a pretty big dive... Got access to an oscilloscope so you can confirm that's what's doing it?
The AVR has a clean/regulated power supply, PVCC sense going into the AVR is filtered, and the AVR is sitting on the low current half of the board, so I doubt there's any conversion error.
That's a pretty big dive... Got access to an oscilloscope so you can confirm that's what's doing it?
Preflight sanity check time.
Working great wired up on the bench. Now it's cased up with new 20K stepped attenuator and Cinemag input transformers and ready for first power-up. RCA and speaker jacks check out OK with ohmmeter. PS is a lovely 18V.
I noticed some folks isolate the Wiener with plastic standoffs and plastic nuts/bolts. Why? Also, how best to handle the white (shield?) Cinemag wire - just tie to chassis ground at a convenient location?
BK
Working great wired up on the bench. Now it's cased up with new 20K stepped attenuator and Cinemag input transformers and ready for first power-up. RCA and speaker jacks check out OK with ohmmeter. PS is a lovely 18V.
I noticed some folks isolate the Wiener with plastic standoffs and plastic nuts/bolts. Why? Also, how best to handle the white (shield?) Cinemag wire - just tie to chassis ground at a convenient location?
BK
An externally hosted image should be here but it was not working when we last tested it.
Primary. I figured secondary would need a balanced type pot. I have to admit I didn't think the whole implementation through, and if I need to I'm prepared to remove the attenuator and control volume at my DAC.
As for the CineMag, I'm very much following your lead rhing!
BK
Making music and working, but producing a bit of annoying speaker buzz. Silent the first few clicks, then quite noticeable at 1/2-3/4, then silent at full open. It's a nearfield setup, so the buzz is a problem. Hoping I won't regret the single-case setup! Is there an alternative grounding or board mounting method that might solve my issue?
BK
BK
In addition to what irribeo recommended about using the Nylon standoffs to avoid ground loops, I would move the volume pot to your DAC rather than have it wired across the primary windings of the input transformers. Either that, or you'll need a pair of volume pots (or a matched four-gang attenuator) and some resistors across the two input transformer secondary windings.
Here's my setup:
An externally hosted image should be here but it was not working when we last tested it.
