The Soft as a Feather Pillow Plus (SFPP) soft start with remote on/off has been built and tested working now with the momentary pushbutton switch with ring light LED. Now install it on the top lid underside.
On the bench tonight - the Deltic amp is finally done. Complete with soft start and SSR on/off with lighted pushbutton switch. Solid state speaker protection relays. Front panel volume pot. Manley RCA jacks.
It works very well. The front panel soft start pushbutton makes it feel like a commercial amp. It is still absolutely silent with no music playing. Measures 0.0mV rms at speaker output with music paused.
Helper PCB for strain relief on volume pot:
It works very well. The front panel soft start pushbutton makes it feel like a commercial amp. It is still absolutely silent with no music playing. Measures 0.0mV rms at speaker output with music paused.
Helper PCB for strain relief on volume pot:
Nice! I get up to 5mV offset out of transformer coupled tubes! (because the gNFB loop connects the speaker to the cathode of the first tube through a 2k resistance.) I just checked my MA-1-6P36S amp and it read 0.1mV though 🙂
Any plans to make a standard 17" wide version of it?
Any plans to make a standard 17" wide version of it?
We are exploring the possibility of this becoming a commercial amp in the same chassis as the A40. Maybe only 300mm deep though.
Not 304mm? I figured being in the USA, you'd design in inches 🙂
That's my standard chassis size for my amplifiers. 17"x12"x2" but I use 10" deep for the Little Miracle since it's a smaller design.
That's my standard chassis size for my amplifiers. 17"x12"x2" but I use 10" deep for the Little Miracle since it's a smaller design.
I used to work in inches but the design team and manufacturing team is global and hardware is mostly in mm dimensions so I have settled on using mm but the width I try to keep close to allow to fit in a standard EIA “17 inch” wide equipment rack or 430mm in this case.
When I go into SolidWorks now I use mm by default.
The 300mm depth is depth of heatsink. Actual chassis with corner hardware is 25mm deeper for 325mm deep. On the 350mm heatsink the total depth is 375mm.
When I go into SolidWorks now I use mm by default.
The 300mm depth is depth of heatsink. Actual chassis with corner hardware is 25mm deeper for 325mm deep. On the 350mm heatsink the total depth is 375mm.
My largest is 17x14x3 - Used for my largest modular.
650VA PT and 250VA x4 for OPT (two per channel). Fitting it all into 12" is a giant pain in the butt.
650VA PT and 250VA x4 for OPT (two per channel). Fitting it all into 12" is a giant pain in the butt.
Okay then XRK 🙂
You posted in the Xmas thread that I should post some bench photos here as well!
Recently I did a ClassD filter, where I found the schematic somewhere on the net.
I have "some" Class D amplifier's to test, and I need the filter to avoid high switching aliasing noise on my measuring-rig.
So the filter most rolloff the responce from 20kHz and forth to avoid this "ghosting"...
When I tested the filter, I used the Joy-IT signal generator and my scope for an automatic bodeplot.
I was looking at the scope when running, and the amplitude was near zero around 150kHz as expected.
I still have to test it in real world setup with a DUT classD amplifier through.
Jesper.
You posted in the Xmas thread that I should post some bench photos here as well!
Recently I did a ClassD filter, where I found the schematic somewhere on the net.
I have "some" Class D amplifier's to test, and I need the filter to avoid high switching aliasing noise on my measuring-rig.
So the filter most rolloff the responce from 20kHz and forth to avoid this "ghosting"...
When I tested the filter, I used the Joy-IT signal generator and my scope for an automatic bodeplot.
I was looking at the scope when running, and the amplitude was near zero around 150kHz as expected.
I still have to test it in real world setup with a DUT classD amplifier through.
Jesper.
BACK onto the BENCH!...
I found some info here : https://www.diyaudio.com/community/threads/passive-filter-for-class-d-amp-testing.277076/page-5
But I also found some info on the Cosmos Discord channel.
I'ts actually been sitting there without any use for some time now 😕
Jesper.
I found some info here : https://www.diyaudio.com/community/threads/passive-filter-for-class-d-amp-testing.277076/page-5
But I also found some info on the Cosmos Discord channel.
I'ts actually been sitting there without any use for some time now 😕
Jesper.
Cool. I built this close to a “brick wall” filter a couple years ago for Class D amp tests. It works quite well. 100kHz frequency. I got it from someone on the TPA3255 thread.
https://www.diyaudio.com/community/threads/whats-on-the-bench-tonight-obt.372508/post-6714905
Above is a 600w fan cooled 5ohm non inductive dummy resistor made from paralleled 10ohm EBG UXP-300 flat thin film resistors.
https://www.diyaudio.com/community/threads/whats-on-the-bench-tonight-obt.372508/post-6714905
Above is a 600w fan cooled 5ohm non inductive dummy resistor made from paralleled 10ohm EBG UXP-300 flat thin film resistors.
Looking at that bench and then my two benches...I needs to clean up. I'm a SLOB - and I dont mean the speaker design ;')
Jesper definitely gets the vote for the neatest bench! I have 3 and each is progressively messier.
On the bench tonight is the new XSA Labs bookshelf TL speaker. I just received it and installing the drivers. The bamboo front baffle is CNC machined perfectly and has a very nice oiled and hand rubbed satin finish. The satin finish piano black paint on the rest of the cabinet also looks superb. Very beautiful for and finish as you can see.
Too late for a loud listening test but sound is as expected and so far so good.
Too late for a loud listening test but sound is as expected and so far so good.
Looks fabulous, X. How are you handling stuffing? Are the screwed in baffle and binding post plate enough for access, or did your cabinet maker install the stuffing?
The eggcrate foam is preinstalled. I add stuffing to chamber behind drivers.
7.5in W x 14.0in H x 14.0in D
Basically same baffle as Vanguard but with a vent on bottom that adds 2in to height and 14in deep.
Basically same baffle as Vanguard but with a vent on bottom that adds 2in to height and 14in deep.
I think I had better spend more time here
I'm learning SO MANY THINGS 😉😀😵
I'm learning SO MANY THINGS 😉😀😵
On the bench is the XSA Labs TL.
A quick measurement of the TL with a basic XO shows a pretty nice response. 83dB at 2.83v and 1m. -3dB at 50Hz and -6dB at 41Hz. I’m going to rework the crossover to get it a bit smoother. But it actually sounds excellent as is.
A quick measurement of the TL with a basic XO shows a pretty nice response. 83dB at 2.83v and 1m. -3dB at 50Hz and -6dB at 41Hz. I’m going to rework the crossover to get it a bit smoother. But it actually sounds excellent as is.