The "Un-Case" 2U amplifier enclosure
2U front panel with all connections (except IEC socket) on front. Heatsinks serve as side walls. Plywood base panel. Open circulation top. Clean functional rack mount amp case for cost of $8 2U panel.
Still laying out arrangement but will be completed soon. Here is Abletec 53v dual rail SMPS version.
2U front panel with all connections (except IEC socket) on front. Heatsinks serve as side walls. Plywood base panel. Open circulation top. Clean functional rack mount amp case for cost of $8 2U panel.
Still laying out arrangement but will be completed soon. Here is Abletec 53v dual rail SMPS version.
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2U front panel with all connections (except IEC socket) on front. Heatsinks serve as side walls. Plywood bad panel. Open circulation top. Clean functional rack mount amp case for cost of $8 2U panel.
Still laying out arrangement but sill be completed soon. Here is Abletec 53v dual rail SMPS version.
Very good for the price 😉
Cool 🙂
I hope you enjoy the build and the sound 😎
Let us know if you will have some questions or need assistance
Let the fun begin. 🙂 it's a very pleasant easy board to build. Do spend time matching the Hfe's on the input transistor pairs. You will be rewarded with rock solid 0-1mV offset and low distortion.
I made up some new CRC cap bank filters with 4700uF and 5R and 4700uF with a 330pF snubber on input and 100nF bypass on output. Using the 53v Abletec SMPS, I am measuring 0.1mV AC ripple at the amplifier output with the audio inputs grounded. Now that's quiet!
I made up some new CRC cap bank filters with 4700uF and 5R and 4700uF with a 330pF snubber on input and 100nF bypass on output. Using the 53v Abletec SMPS, I am measuring 0.1mV AC ripple at the amplifier output with the audio inputs grounded. Now that's quiet!
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Hallo X.
I have seen your newest stroke DX-PSU with CLC 1000µ huge cap bank.
Can you also publish here please?
Are there Boards anywhere?
Valery what did you say about that Filtering?
Hi meanman, could i hooked you in to the nice guys here?- he......he......he.
I am to slow, later i also will build the single VHex.
Valery, the Ampliwire boards are stuffed partially now....always slow.
Best Regards Bangla.
I have seen your newest stroke DX-PSU with CLC 1000µ huge cap bank.
Can you also publish here please?
Are there Boards anywhere?
Valery what did you say about that Filtering?
Hi meanman, could i hooked you in to the nice guys here?- he......he......he.
I am to slow, later i also will build the single VHex.
Valery, the Ampliwire boards are stuffed partially now....always slow.
Best Regards Bangla.
Cool 🙂
I hope you enjoy the build and the sound 😎
Let us know if you will have some questions or need assistance
Thank you!
I'm waiting for my parts to arrive from Mouser. In 2 or 3 days I'll start soldering 😉
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0.1mV is no ripple at all! 😱
How did you arrive to the snubber values? And how do you get away with 5R resistors? What happens with rail voltage when the amp starts needing lots of current? I'd love to have a 5R resistor in my CRC...
Hi Bangla, that filtering looks good to me. I did not test CLC myself, however X did some careful measurements (and listening) with good results. Important thing, influencing the sound stage, is having separate rectofiers and filter banks for each channel.
VHex is fun to build and it starts seamlessly if all the parts are good and no mistakes are made 😉
VHex is fun to build and it starts seamlessly if all the parts are good and no mistakes are made 😉
I've have two DX psu boards from Rudi Ratlos
Ampliwire boards ????????
For nice PSU boards look at Jims Audio
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Ampliwire boards ????????
Hallo MM and Val.
You answer faster than a shoot ! ! ! 😀
The "Amplwire IPS"- is Valerys InPutSektion- Board in look to fix with OS-
Slewmaster Board worked out, so i would fix it with Baby Slew LatFet Board.
Val can clear it better.
And yes we are talking about double mono.
xrk knows the posted psu in Miles 100W ultimate..... looks good.
cheers Bangla.
Hallo MM and Val.
You answer faster than a shoot ! ! ! 😀
The "Amplwire IPS"- is Valerys InPutSektion- Board in look to fix with OS-
Slewmaster Board worked out, so i would fix it with Baby Slew LatFet Board.
Val can clear it better.
And yes we are talking about double mono.
xrk knows the posted psu in Miles 100W ultimate..... looks good.
cheers Bangla.
Right, Ampliwire is just a front-end section of VHex - that's the way VHex was born (thanks to Abetir, Terry and Idefixes for certain inspiration and a lot of good work with early prototypes 😉).
I have not driven it hard yet (too loud) so maybe there might be some voltage sag for sustained high current. However, the Abletec SMPS, is rated for 1.38 amps continuous, 4.13 amps for 5 minutes, and 16.5 amps for 10ms. In all seriousness, the 4.13 amps would be a peak situation and since it powers two CRC's that is about 2 amps max current each.
Model Alp0400-6000
http://www.parts-express.com/pedocs/specs/129-147-parts-express-specifications.pdf
At 2 amps current, that would be a 10 volt sag (V=IR) from 52v to 42v rails. I suppose (as suggested by PauloPT) I could put an MUR12xx diode across the 5R to handle the high transients?
For now, at the power levels I am playing it doesn't seem to lack any headroom.
The snubber choice is purely from my experience in trying to suppress RF switch noise above 400kHz from class D amps. 330pF and 4.7R to 10R seems to do the trick well.
The 100nF 100V film bypass caps are just another typical value to use to achieve suppression of transient noise and is de-rigeur as placed next to all electrolytic caps on main amp PCB's.
I am wondering if I should leave a diode in between the SMPS and CRC to make sure the two filter banks are truly de-coupled.
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I mean this #7758 100W Ultimate Fidelity Amp.
http://www.diyaudio.com/forums/atta...-ultimate-fidelity-amplifier-psu-cap-bank.jpg
http://www.diyaudio.com/forums/atta...-ultimate-fidelity-amplifier-psu-cap-bank.jpg
It would probably be worth taking some measurements of the output distortion to see if a CRC or CLC supply is actually helping. The front end of the VHex is regulated, so ripple likely wouldn't be reaching it.
I got that cap bank board from a friend as a gift. I can check to see if more are available if interested.
It has room for qnty 2 x 22,000uF caps (I am only using two 4700uF) and qnty 40 x 1000uF caps. It is an LC filter board (currently L is 2.5mH CMC) but I added my usual 330pF snubber and 100nF output bypass. The ESR is < 3milliOhm (estimated from ESR of one cap). It is like lightning in a bottle for bass transients 😀
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I just asked vzaichenko what he uses for HD spectrum measurements. I am in process of putting together a DIY measurement system for my amps now. Looking for an affordable low THD sound card (USB).
That makes sense that the Vhex has on-board regulation - as the ripple is remarkably low. I am estimating a PSRR of -70dB or better?
All I see is a LED controlled CCS - how is the regulation performed?
ripple likely wouldn't be reaching it.
Hallo Jwilhelm.
That's nice to read.
I use the mm advised Jims Audio Board CRC in Pass Amps. For my lazy ears
soundstage and separation is very clean.
Here a rewired F4- to much heat- needs extra cooling for Rectifier 35A- Typ
and so on...
Hallo Jwilhelm.
That's nice to read.
I use the mm advised Jims Audio Board CRC in Pass Amps. For my lazy ears
soundstage and separation is very clean.
Here a rewired F4- to much heat- needs extra cooling for Rectifier 35A- Typ
and so on...
Attachments
board from a friend as a gift.
Hi X.
All cleared. What would say Valery: necessary PSU? a good to do?
The idea THD measuring diy, great if possible.
Cheers Bangla.
Hi X.
All cleared. What would say Valery: necessary PSU? a good to do?
The idea THD measuring diy, great if possible.
Cheers Bangla.
The only part of the amp that sees rail voltage is the output devices. Voltage is dropped through diodes (D5 & D7) to the drivers, then fed to the VAS and front end through 22R resistors. The front end is then fed through paralleled 3k6 resistors(R11-14) and then regulated by zeners (D1 & D2), and filtered/decoupled by C2, 3, 4 & 6 . By the time voltage gets to the sensitive front end, pretty much the only noise on the line will be from the zeners themselves.