Thanks @rockies914 - yes, one can arrange the windings to match the speaker load.
Be careful to note the MINIMUM impedance of the speaker (usually down in the bass below 100Hz, but often much more complex), not the average impedance.
As per the previous post with the dual-chamber quad-filar wound bobbin, the best performance in THD and Damping-Factor will always be with all four secondary windings in parallel.
Many here buy old inverter heatsinks from this eBay seller who accepts offers, so that part is now easy. I am also struggling with finding other cheap parts for amp cases that don’t require too much reworking.
Thanks.
None of my speakers drop below 5 Ohm, but quad-filar seems to be the most versatile option (iot avoid 'another' DF debate/rabbit hole).
Electrical wall boxes with gland plates, for example:
https://www.rittal.com/com-en/products/PG20231215SCH101/PG20231215SCH201/PRO70535?variantId=1535000
... which is the one I used for my original preamp.
For the ones I used in the new amps the boxes only have one gland plate. The back side needed cutting out to expose enough heatsink area to mount the MOSFETs, but as it isn't visible it doesn't have to be perfect. I have a Bosch nibbler for this sort of thing. It's a fearsome beast, but munches through the steel with alacrity!
Progress with my new Pre-Amp/Line-Driver chassis... the rear panel cutouts and the drilling for the two heatsinks is done and I have been able to put it together for the first time this evening.
I very much doubt I will use all seven M3 mounting points on each heatsink, but easier to put them in now and use as required.
Next up is the front-panel which will need a bit of thought as to the layout. Fortunately I have a couple of "rough" aluminium plates of the right size so I can try out the arrangement I have in mind before committing to machining the actual front panel piece which is already anodised.
N.B. It is being built as a dual-mono hence the two Cliff power-connectors and fuse-holders.
I very much doubt I will use all seven M3 mounting points on each heatsink, but easier to put them in now and use as required.
Next up is the front-panel which will need a bit of thought as to the layout. Fortunately I have a couple of "rough" aluminium plates of the right size so I can try out the arrangement I have in mind before committing to machining the actual front panel piece which is already anodised.
N.B. It is being built as a dual-mono hence the two Cliff power-connectors and fuse-holders.
Not since the early 90's when I sold my last tape deck.
I love analog, but I detest storing (too much) stuff even more.
I love analog, but I detest storing (too much) stuff even more.
Yeah I love the sound that tape gives, but I also bailed years ago 🙂 Not only storage but maintenance, even if a good name brand unit can be real reliable.
Man I feel old.
Man I feel old.
Speaking of which... I think your CDP is as brilliant as your amplifier topology:
DACs are PCM63s?
DACs are PCM63s?
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PCM1702s...
https://www.sowter.co.uk/dacinfo/PCM1702.pdf
... the only DACs that are better are the PCM1704s!
Sadly, it seems that the only '04s available are all fakes.
The best alternative (to my ears) I have found are the PCM1794As in dual-mono mode - as in the pic below which is my OPPO980H upgrade.
I initially suggested 1702/04s, but changed this as I thought these chips were not available at the time you built the CDP.
179.. series are indeed among the better (sounding) ΔΣ DACs. Some people seem to believe that DAC chips inherently have very little sound signature and that implementation matters (most). While there's some truth to that line of thinking, I have yet to hear an ESS DAC that I actually like (and I own several).
Original 1702/04 chips are still offered for sale, but usually cost > €100 each.
179.. series are indeed among the better (sounding) ΔΣ DACs. Some people seem to believe that DAC chips inherently have very little sound signature and that implementation matters (most). While there's some truth to that line of thinking, I have yet to hear an ESS DAC that I actually like (and I own several).
Original 1702/04 chips are still offered for sale, but usually cost > €100 each.
I bought some 1704 chips a decade or so ago, but I am pretty sure they are fake.
Yet another "Round-2-it project" that I haven't had time to get at. 🙁
To my ears the ESS DACs (in our Oppo) are fine for watching movies, etc. but they sound slightly off to me too!
It's difficult to describe exactly, and I am being picky. I just don't like brick-wall filters.
Basically I understand the technical reasons for ΔΣ DACs, but a 1702/4 with a slow-rolloff filter is so much nicer (with the right source material of course).