Yes, those caps are a little larger, perhaps 1206 size - I'm sure Richard will be able to confirm.
I finished the Xen I/V boards!
Here's a sneak preview of the Maxed-Out AMP, not quite ready to go yet but you might get the general idea.
I took up the idea of the add-on board when I realized the wires to the caps themselves would be longer than the interconnections between boards. So the crazy caps (Duelund?) can be accommodated on the plug-in PCB. The 'monster' sized (25mm dia) cap replacing the 3300uF has been deleted as I've found the chip takes an inordinately long time to power-up even with only 15,000uF in that position. The LM317 has LV's denoiser as option as well as space around for a Sparkos. We've had to guess on the pinout of the Cinemag.
I took up the idea of the add-on board when I realized the wires to the caps themselves would be longer than the interconnections between boards. So the crazy caps (Duelund?) can be accommodated on the plug-in PCB. The 'monster' sized (25mm dia) cap replacing the 3300uF has been deleted as I've found the chip takes an inordinately long time to power-up even with only 15,000uF in that position. The LM317 has LV's denoiser as option as well as space around for a Sparkos. We've had to guess on the pinout of the Cinemag.
Nice work Richard and thankyou. Looking good.
Just one thing that crossed my mind is that do I recall that a denoiser raises the voltage a bit over a vanilla 317 set up?
Thinking out loud here....if we used different supplies to feed 2 x 21v, is the ramp up time important.? Does it matter if they don't come up at the same time?
Just one thing that crossed my mind is that do I recall that a denoiser raises the voltage a bit over a vanilla 317 set up?
Thinking out loud here....if we used different supplies to feed 2 x 21v, is the ramp up time important.? Does it matter if they don't come up at the same time?
I'm not sure about ramp-up time, I think probably not too important. But what is important is the VDDA (signal supply) can't go higher than the VDDP (output supply) which is why there's a diode (D6) between the two. So with separate supplies the output stage supply needs to ramp up first, or simultaneously with the signal supply.
We'll adjust the ADJ resistor value for denoiser operation if it raises the output voltage.
We'll adjust the ADJ resistor value for denoiser operation if it raises the output voltage.
Today I managed to squeeze an ACA CLC filter for the SMPS into my MonoAmp project and I'm listening to the result as I type this - a small but worthwhile improvement and definitely worth including on the hot-rodded MonoAmp.
It was a bit of a squeeze in my tiny chassis but achieved with a little surgery to the filter board and by turning it upside down.
The project just needs a front panel now, which I'll probably get 3D printed, for the lid to be put on this project.
It was a bit of a squeeze in my tiny chassis but achieved with a little surgery to the filter board and by turning it upside down.
The project just needs a front panel now, which I'll probably get 3D printed, for the lid to be put on this project.
Volume control/buffer board taking shape on my bench. We were able to find a consignment of recycled ERO MKCs (long discontinued I understand) on Taobao. ALPS RK27 still to be fitted plus various 'lytics. Initially I've located the mains trafo top right but now I'm rather skeptical that'll give a hum-free experience so I'm thinking it may well end up off-board.
I've already got a suitable volume and buffer solution Richard - it uses the same small chassis as my MonoAmp project and I am going to get a front panel done for the MonoAmp to match.
The volume control uses a Muses chip, power supply is a SilentSwitcher and the buffer output uses the amazing vintage BUF-03 devices - now, if you could obtain a batch of BUF-03s on taobao that would be really special, though genuine ones are like hen's teeth - I'm very fortunate to have a couple of spares.
The volume control uses a Muses chip, power supply is a SilentSwitcher and the buffer output uses the amazing vintage BUF-03 devices - now, if you could obtain a batch of BUF-03s on taobao that would be really special, though genuine ones are like hen's teeth - I'm very fortunate to have a couple of spares.
I've fallen out of love with BUF-03 since you mentioned it last time which inclined me to have a careful look at its DS. Its way too noisy for use as a line driver with a noise spec of 60nV/rtHz at 10kHz and no noise plot vs frequency shown.
As a comparison (just for noise, not any other attribute) a TL072 is typically 18nV/rtHz and that's a noisy beast. BUF-03 is 10dB noisier than that in the best case.
As a comparison (just for noise, not any other attribute) a TL072 is typically 18nV/rtHz and that's a noisy beast. BUF-03 is 10dB noisier than that in the best case.
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But it sounds fantastic!
Anyway, the point I was making with my post is what a neat little system you can assemble with your kits - I'll likely house my Kubelik DAC and STA333BW HPA in the same arrangement.
'tis OK Richard, I didn't read anything personal into your observation about the BUF-03, it just illustrates that things are never simple...
On the digital display, it's all controlled by the Academy Audio Muses volume control module
https://www.academyaudio.com/product-page/vcu-hi-end-muses-micro-volume-control-board
This is DIY Audio so I hacked it a little to install the display and relocate the IR remote control receiver but otherwise it's 'out of the box' - sounds good too.
Looking great Richard, shame on the separate board for the crazy caps but the scale is crazy when looking between the boards haha. Great stuff, you are a genius and a gentleman, thanks for the great work and to your wife for her effort too! : )
Happy New Year all... although I guess yours is in February Richard isn't it?!
I was going to use a Salas L adaptor per channel for the supply for the 24v but I've just found in my stash a 200W/8A Meanwell SP200-24. So I think it would be prudent to use that as it save me buying the power trafo for the L Adaptors. Although I just today found some 150va 24v toroidal on ebay for £15. I've also been reading the Mark Johnson thread on his small post smps filter...good for 3A. I've ordered some boards and shall try one per amp channel. Maybe overkill with the trafo input but I have no clue on that!
My vanilla mono amp boards are on their way from JLCPCB!
I was going to use a Salas L adaptor per channel for the supply for the 24v but I've just found in my stash a 200W/8A Meanwell SP200-24. So I think it would be prudent to use that as it save me buying the power trafo for the L Adaptors. Although I just today found some 150va 24v toroidal on ebay for £15. I've also been reading the Mark Johnson thread on his small post smps filter...good for 3A. I've ordered some boards and shall try one per amp channel. Maybe overkill with the trafo input but I have no clue on that!
My vanilla mono amp boards are on their way from JLCPCB!
Speaking of monoAMP boards, we also have some revised ones coming from JLCPCB. Just a couple of mods - first to replace the 2R2 with an inductor and second to add the footprint of the Aliexpress trafo as an option.
I have investigated the MJ filter and think I can include a similar one when we respin the AMP-to-11 board. Rather than include those low-value resistors for damping I'll go for adding damping at the output.
Jim - yes Chinese New Year (Tiger) is Feb 1st this year (had to look it up), relatively early.
I have investigated the MJ filter and think I can include a similar one when we respin the AMP-to-11 board. Rather than include those low-value resistors for damping I'll go for adding damping at the output.
Jim - yes Chinese New Year (Tiger) is Feb 1st this year (had to look it up), relatively early.
Ah pity I ordered the previous version pcb as I was going to go Aliexpress trafo! I havent actually ordered them yet, was considering asking you how much to send a couple of yours?! But then to make postage viable I may aswell get some other stuff from you.!!
We've booked into the local Chinese restaurant in early Feb!
We've booked into the local Chinese restaurant in early Feb!
If you only want PCBs its normally cheapest to get JLC to send you direct, I don't know how they get such cheap shipping rates. The PCBs themselves are very cheap, normally well under 1UKP each even for big ones. Happy to throw in a couple of our new ones for free if they turn out to work, I'd prefer to test one first before sending. I can't remember if we ordered them blank or with some parts pre-stuffed. If you're getting stuff from us via courier the first 500g is relatively expensive, subsequent 500g increments are considerably cheaper.
What are your favourite dishes at the Chinese emporium? I used to be a sucker for Beijing Duck with pancakes and hoisin sauce back in UK but that style of duck I've not come across here, the locals seem to like it more moist.
What are your favourite dishes at the Chinese emporium? I used to be a sucker for Beijing Duck with pancakes and hoisin sauce back in UK but that style of duck I've not come across here, the locals seem to like it more moist.