Which cinemag transformer, if you don't mind? I see several with 1:4 winding or tap ratio.
Last edited:
I know... I'm looking for a Dynaco like enclosure... BUT, a big humidor will be nice... I found some power supplies at Parts Express.... the only caveat will be heat management. Or just open the lid when I listen to music. I could put a small PC fan on the lid and cut some slots on the back...
An "imperfect" humidor that holds 200 cigars will fit the parts inside.
Note: I have several humidors... one of these. It's pretty big although the drawers at the base are separate... although nice storage. The thing is big enough to handle two Zons Of Zenductor II, a power supply and the wiring (and fan).
https://www.cigarhumidors-online.co...he-windsor-300-count-burl-cigar-humidor.html#
It'll match the B1 in a humidor perfectly too. A couple of nice wooden humidors holding a stereo might make my wife happier. The set up would work great with the Metronomes.
The next question is the RCA connectors... do I pull them off and use a set on the back of the box or just fish the RCA cables through and do minimal damage to the amps?
Work really gets in the way of my life...
Last edited:
Nice wooden boxes. I'm not sure though the drawer fronts are all that practical. I assume you would cut off the drawers, and glue the fronts on?
For the heat sinks, I'm thinking 40mm fans mounted right on top could make them work inside an enclosure. The enclosure still needs a hole or hole pattern or mesh right above the fan.
Alternatively, if you still wanted a wooden enclosure, but a larger heatsink, how about a large but relatively shallow heatsink sitting on top of a large slow running fan as the base for the whole enclosure, with the two output transistors relocated to to be bolted to that heatsink? There would need to be feet, so that the fan doesn't sit directly on whatever supports the amp enclosure, and the heatsink channels need to have a clear view to an exhaust path, on two of the four enclosure sides.
I believe the existing speaker posts are long enough to be reused going through a wooden enclosure wall, by just leaving out the two black plastic spacer pieces.
For the RCA input, I think one needs a different socket. It seems there are quite a few available that should work with a 1/4" thick wall (about 10mm thread length), e.g. https://www.amazon.com/dp/B0D8FJNN8D/ .
Alternatively one could position the board with the existing soldered-in jack right against the back wall, and drill a hole large enough for the male RCA plug through the enclosure, but then you push on the board when plugging in the input cable, which is not ideal.
For the heat sinks, I'm thinking 40mm fans mounted right on top could make them work inside an enclosure. The enclosure still needs a hole or hole pattern or mesh right above the fan.
Alternatively, if you still wanted a wooden enclosure, but a larger heatsink, how about a large but relatively shallow heatsink sitting on top of a large slow running fan as the base for the whole enclosure, with the two output transistors relocated to to be bolted to that heatsink? There would need to be feet, so that the fan doesn't sit directly on whatever supports the amp enclosure, and the heatsink channels need to have a clear view to an exhaust path, on two of the four enclosure sides.
I believe the existing speaker posts are long enough to be reused going through a wooden enclosure wall, by just leaving out the two black plastic spacer pieces.
For the RCA input, I think one needs a different socket. It seems there are quite a few available that should work with a 1/4" thick wall (about 10mm thread length), e.g. https://www.amazon.com/dp/B0D8FJNN8D/ .
Alternatively one could position the board with the existing soldered-in jack right against the back wall, and drill a hole large enough for the male RCA plug through the enclosure, but then you push on the board when plugging in the input cable, which is not ideal.
I have one of those humidors. The top interior is large enough that you don't need to mess with the lower drawers at all. If anything, you could cut slots in between the two compartments, cut two slots in the lower rear of the humidor and the drawers, put two small fans and push some air upwards through the upper cavity... From the front you would never see the difference.
Or you could cut holes on the underside, and the drawers... mount a fan on each drawer with a long power cable so the drawers stay functional and draw air from below the humidor ( with legs of course ).
Quite likely the easiest thing to do is to open the lid when running. Maybe put a heat controlled thermostat switch to OFF/ON the power. I have one of those in the server closet, running a fan that sucks air out the top of the door.
This might be as easy as stuffing everything into the box and then redoing the power supply. I thin the first stop will be to mount the whole thing on a perforated metal "basket" that can be inserted into the humidor and then figure out the ins and outs...
Mount the amps and power bricks to this and lower it into the humidor. I just measured, it will fit...
https://www.amazon.com/YBM-1118-Sto...07&mcid=9d3850acc2e837e08765e86a4e5a4536&th=1
BTW, I just checked the power supply boxes I brought from BA.... they are 16V, did I screw up? I haven't powered up those amp yets.
Or you could cut holes on the underside, and the drawers... mount a fan on each drawer with a long power cable so the drawers stay functional and draw air from below the humidor ( with legs of course ).
Quite likely the easiest thing to do is to open the lid when running. Maybe put a heat controlled thermostat switch to OFF/ON the power. I have one of those in the server closet, running a fan that sucks air out the top of the door.
This might be as easy as stuffing everything into the box and then redoing the power supply. I thin the first stop will be to mount the whole thing on a perforated metal "basket" that can be inserted into the humidor and then figure out the ins and outs...
Mount the amps and power bricks to this and lower it into the humidor. I just measured, it will fit...
https://www.amazon.com/YBM-1118-Sto...07&mcid=9d3850acc2e837e08765e86a4e5a4536&th=1
BTW, I just checked the power supply boxes I brought from BA.... they are 16V, did I screw up? I haven't powered up those amp yets.
Last edited:
Sometimes I am hesitant to ask questions for fear I'm asking are dumb question, or one that's been obviously answered before....but....here I go anyway...
If I recall correctly Nelson's talk at BAF'24 mentioned that one could use a higher voltage power supply (say those old Dell laptop 19.5V), but the heat sinks are the limiting factor. If one used the "skyscraper" approach to double the heat sink area, is there any other components that would not like a 19.5VDC input? One would keep bias at the same 1.4-1.5A, so the choke should still be in limits if I'm not mistaken. I'm just curious mostly. I see that the Zenductor II article already notes that at 16V, the heats sinks are smokin' hot and outputs 10W at 1.5A bias. Not really thinking it gains one much bumping up the voltage by 23% other than a slightly warmer room in the end, and wanted to ask anyway to learn and understand 🤔
If I recall correctly Nelson's talk at BAF'24 mentioned that one could use a higher voltage power supply (say those old Dell laptop 19.5V), but the heat sinks are the limiting factor. If one used the "skyscraper" approach to double the heat sink area, is there any other components that would not like a 19.5VDC input? One would keep bias at the same 1.4-1.5A, so the choke should still be in limits if I'm not mistaken. I'm just curious mostly. I see that the Zenductor II article already notes that at 16V, the heats sinks are smokin' hot and outputs 10W at 1.5A bias. Not really thinking it gains one much bumping up the voltage by 23% other than a slightly warmer room in the end, and wanted to ask anyway to learn and understand 🤔
Looking at 6L6's pictures, C2, C5, and C6 are 25VDC rated. These three capacitors see the power supply voltage (or close to the power supply voltage) but since their rating is higher than 19.5V, they are good. The other capacitors are also good.
The increased power supply voltage will make the LED shine brighter. I do not know the maximum current for the LED so to be safe, replace the 2.2k resistor with a higher value. The value is not critical as LEDs are now very bright. Even a 20k resistor will make the LED shine brightly.
The increased power supply voltage will make the LED shine brighter. I do not know the maximum current for the LED so to be safe, replace the 2.2k resistor with a higher value. The value is not critical as LEDs are now very bright. Even a 20k resistor will make the LED shine brightly.
If you have the sinks (or no fear) you can go 19.5 V, but at some point you meet diminishing returns, depending on the load, a function of saturation in the Inductor. With this inductor it occurs above about 1.5 amp bias.
So, if I up the power supply to 18V... and add taller heat sinks... other than the LED being bright... I'm I safe setting the bias at 1.5V?
I don't see many power supplies at 16V, but quite a few for 18V... It would allow me to put a single Mean Well power supply in the box.
What would the power be?
Assuming the gain is the same, mostly what I'd be looking at is higher peak power, is that it? Could I get 15 wpc?
Mostly, I'm not after more power, but just finding a single power supply that I can fit in the box. In reality, 10wpc is more than I need for this application.
I don't see many power supplies at 16V, but quite a few for 18V... It would allow me to put a single Mean Well power supply in the box.
What would the power be?
Assuming the gain is the same, mostly what I'd be looking at is higher peak power, is that it? Could I get 15 wpc?
Mostly, I'm not after more power, but just finding a single power supply that I can fit in the box. In reality, 10wpc is more than I need for this application.
It makes sense that you've designed this amp for optimal use with a 16V PSU. My curiosity was sparked when the mention of more voltage just means higher heat sink temperatures for all practical purposes. Thank you to Ben and Papa for your quick responses. I can sleep well pondering "what if" now, just for fun and learning. Thank you!
Now back to the regularly scheduled program.
Now back to the regularly scheduled program.
That part number is 2.5" high... not the skyscraper version...
Before you go to sleep, @birdbox, what is the part number for the skyscraper version?
Last edited:
If I use some Loctite Red in the "threads"... will that block the heat flow? Or can I use some Loctite in there and use the thermal grease between the base/top of the heat sinks proper? Will that be sufficient to allow heat transfer?
It's a press fit. There are no threads as the "posts/dowels" fit into the heat sink extrusion. Not sure lock-tite buys you much, if anything. Stacking the heat sinks is just a risk mitigation to try out for me. I am doing it so I can run 1.5A bias and not have crazy hot heat sinks with a toddler and curious cat in the house. Trying to avoid human, and/or animal, sacrifices. No "burny burny cut cut".
Last edited:
What have the Romans done for us?
Well.. Nelsonius Passius has done a lot, eh? Gratia Plena Nelsonio... (*)
By "threads" I meant the posts. I'll order the parts tomorrow, thanks.
Besides, I mean to enclose the things... but it just looks... "cool" with the tall heat sinks.
(*) I hope I got the noun declension correct...
Well.. Nelsonius Passius has done a lot, eh? Gratia Plena Nelsonio... (*)
By "threads" I meant the posts. I'll order the parts tomorrow, thanks.
Besides, I mean to enclose the things... but it just looks... "cool" with the tall heat sinks.
(*) I hope I got the noun declension correct...
This is rather along the lines of what I was thinking when I asked if anyone was considering a Zenductor 2 Max (post 79). One might mount the mosfets on leads to some larger heat sinks. I presume that there are higher current inductors available. The cooling and the inductor bias limit seem to be the two limiting (power) factors for this amp? I'm not sure to what new vistas of voltage capacity the amp may be transported if these items were addressed.
As secondary factors one might consider higher V rated caps and perhaps a gain transformer that is more than 4:1 (if yer gonna go for it, maybe you want a fancy cinemag or equiv)(but maybe this would make life hard for the fet array?). At some point R6, R7 have a max also.
I'd have to spend some quality time with my old Horowitz & Hill to figure out how it all balanced.
It makes me think of car tuner culture. Sure, you can buy a sporty car and just enjoy driving it around. But if you know what the existing restriction is, that the rest of the machine supports more output, then it kind of calls to you to dig in and get your hands dirty.
Zenductor 2 Fast 2 Furious
At some point (that’s closer then you think) you’ll need a bigger choke and bigger heatsinks… that is to say, the two most expensive things in the amp.
Yes, this basic design is scalable, and it’s going to be interesting to see how people do it. In the time being, look at the MoFo thread for choke recommendations.
Yes, this basic design is scalable, and it’s going to be interesting to see how people do it. In the time being, look at the MoFo thread for choke recommendations.
Finally, after all these years of ZM preaching ........... Greedy Boyz going all Iron
