OS,
I wasn't suggesting to ditch the 5P version, but rather to see if there was serious interest in a different number of native pairs and offer it along side the 5P version. I have altered art for 2P, 3P, 4P and 6P in my Sprint file so it is easy to get a different # of pairs if there is interest.
I do agree the 5P boards can be populated with however many pair a builder might like, which makes them versatile.
And yes, a good PSU, soft-start and DC protect as modules would be good to offer as well so builders can make it a truly complete project. One stop shop
.
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I wouldn't go saying that lots of us are rich, we're building stuff for a reason too
I shall stick with the CFA-XH and see how it performs. (I currently have a TPC blameless CFP and they are no slouch performance wise.)
As it happens my wolverines were made with 95% recycled parts.
As a question though. If this has been posted somewhere then I apologise for asking, but the CFA-XH what exactly is its midband, ie 1kHz, distortion performance like?
I know you've posted lots of high frequency Fourier analyses, but don't remember seeing any low frequency ones.
CFA's exhibit the lowest THD in the 1k-20k+ range ... the PSRR is also best here. PSRR suffers in the LF. More usable NFB gain at HF.
PS - By LF , I mean bass ( <200Hz).
VFA's rule in LF (PSRR , too) , especially the servo'ed ones. "Mega" CLG
at LF is the VFA "way" (70+ symasui , 90+ wolverine).
"Spooky" seems to "bridge" the CFA/VFA gap. Exhibits traits of both.
This is why I'm going to do a new "spooky" Version ... to make LC
eat his words.
OS
OS,
I wasn't suggesting to ditch the 5P version, but rather to see if there was serious interest in a different number of native pairs and offer it along side the 5P version. I have altered art for 2P, 3P, 4P and 6P in my Sprint file so it is easy to get a different # of pairs if there is interest.
I do agree the 5P boards can be populated with however many pair a builder might like, which makes them versatile.
And yes, a good PSU, soft-start and DC protect as modules would be good to offer as well so builders can make it a truly complete project. One stop shop
Just 2 PCB's ,
1- Power supply- softstart/rectifier/capacitor/ + and - 12V aux. "all in one"
board. CRC with 10A diodes across the R - better than ebay or most forum
offerings.then add the common mode choke for AC to it for completeness.
ps- even allow for an external trigger from the "other" board (#2).
2- overcurrent/DC protect board. Monitor the OPS Re's + the output. Trigger
a latching solid state OP relay. Make it "bombproof". Have another
output to "crowbar" the CRC (board #1) into high Z mode for catastrophic failure (big MOSFET's on the CRC).
The "one stop shop" will be my answer to LC's "prank" comment.
I'll show you a prank ! Better stuff , cheaper $'s , no BS ...
OS
I am retired now and on a fixed income. I have a small "allowance" I can use for a hobby. Most of the transformers and heatsinks I have were bought 8 years ago when I was trying to learn this. Most were mistake purchases and just got put on a shelf. So now they are making it possible for me to build some amps by only needing to buy the small components. I also took advantage back then of the sample deal that Onsemi had where you could get lots of 25 pieces of each device and up to 10 different devices per order. I have had a pretty sizable amount of output devices to use without needing to buy any. Hence all the Slewmaster boards I have built. I love the idea this modular setup. This is going to allow me to build a few different topologies without needing to buy more transformers and heatsinks. Love it!
I find it interesting that OS has just declared that VFA is where it is at. I have recently built 6 CFA amps and I don't see them taking a back seat to any of the VFA I have build. Listening to them, there is just nothing missing. I haven't tried driving a sub with one yet. I can try that tomorrow is someone is interested. I have a JBL B360/BX63 I could hook up. Anyway, This is supposed to be a CFA vs VFA and unless someone builds both, how can you call one superior to the other? Looking forward to Jason's next Gerber offering. As soon as he gets those done I will order some more IPS boards. By the end of the month I should have an HP laserjet and will try my hand at etching again.
Blessings, Terry
I find it interesting that OS has just declared that VFA is where it is at. I have recently built 6 CFA amps and I don't see them taking a back seat to any of the VFA I have build. Listening to them, there is just nothing missing. I haven't tried driving a sub with one yet. I can try that tomorrow is someone is interested. I have a JBL B360/BX63 I could hook up. Anyway, This is supposed to be a CFA vs VFA and unless someone builds both, how can you call one superior to the other? Looking forward to Jason's next Gerber offering. As soon as he gets those done I will order some more IPS boards. By the end of the month I should have an HP laserjet and will try my hand at etching again.
Blessings, Terry
You are the best builder on the forum , terry.
When you came to the thread ... I was overjoyed. Thimios is also quite
the "tinkerer" , he uses what he has (like me) ... awesome to have all
this DIYA " power" in one place.
This has stoked my enthusiasm to the point of 3 more IPS's
and the promised protection and power supply offerings.
I've done 6-7 IPS's and 3 OPS's ... I know 5 more "creations" are just
around the corner. I'll be back in mid July. I'm about 2-3 days from
packing this PC in a box (for a month) !!
PS - I'll be exactly 50 YO on 6/11 - the day I move ... crazy.
OS
When you came to the thread ... I was overjoyed. Thimios is also quite
the "tinkerer" , he uses what he has (like me) ... awesome to have all
this DIYA " power" in one place.
This has stoked my enthusiasm to the point of 3 more IPS's
and the promised protection and power supply offerings.
I've done 6-7 IPS's and 3 OPS's ... I know 5 more "creations" are just
around the corner. I'll be back in mid July. I'm about 2-3 days from
packing this PC in a box (for a month) !!
PS - I'll be exactly 50 YO on 6/11 - the day I move ... crazy.
OS
Your assessment is with the majority.... myself included. Will be most curious about OS combo circuit "Spooky" - combining the best of both.
As my music listening priority - the midrange and highs are where the majority of the music spectrum is at... bass comes in second as witnessed by the many high accuracy 2 way speakers systems sold and enjoyed. However, I want it all and am also a bass aficionado so I also use the VFA for bass or 'affects' channel subs.
Lets see what "Spooky" can do.
THx-RNMarsh
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I gave Thimios the "moderate" version of spooky. It can go further.
I worked the first time for thimios - this is good. Not a "dead end".
(basic "spooky" - below 1)
A little more CLG + global gain (from the thimios version)
(below 2) .... huge 150V p-p 20k output @ 4R
gives ... (below 3 ) way better performance than ANY of the IPS's
... CFA included , at this level.
The "breakpoint" is near 10K with 58db CLG , only dropping into the 40's
at 20k+ (similar to a CFA) AND slew is off the scale for a VFA (200v/us+).
I will -
-Add 2Q CCS's with decoupled references.
-reduce Re on the IP pairs for even more CLG.
- Layout an even tighter, perfect IPS PCB for it.
By what I see in simulation , the age old affection for leach amps , and
the stellar reviews for the H/K990 (similar IPS). This might beat them all.
I will ... however , try to keep it simple (no 100 component deals).
Is 82 alright ?
PS - changes mentioned above result in <10ppm /160v p-p/20k/4R
Top "dawg" .
NO WAY a little VSSA can do the 1812 overture cannons any justice -
need the spook at these levels to even begin to recreate this !
OS
I worked the first time for thimios - this is good. Not a "dead end".
(basic "spooky" - below 1)
A little more CLG + global gain (from the thimios version)
(below 2) .... huge 150V p-p 20k output @ 4R
gives ... (below 3 ) way better performance than ANY of the IPS's
... CFA included , at this level.
The "breakpoint" is near 10K with 58db CLG , only dropping into the 40's
at 20k+ (similar to a CFA) AND slew is off the scale for a VFA (200v/us+).
I will -
-Add 2Q CCS's with decoupled references.
-reduce Re on the IP pairs for even more CLG.
- Layout an even tighter, perfect IPS PCB for it.
By what I see in simulation , the age old affection for leach amps , and
the stellar reviews for the H/K990 (similar IPS). This might beat them all.
I will ... however , try to keep it simple (no 100 component deals).
Is 82 alright ?
PS - changes mentioned above result in <10ppm /160v p-p/20k/4R
Top "dawg"
.NO WAY a little VSSA can do the 1812 overture cannons any justice -
need the spook at these levels to even begin to recreate this !
OS
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Terry i can't see these files ,if it's posible please post a picture or a pdf
Thanks.
Please ,can you you post the exactly modification?Increase the input (or gain) , Terry !
My H/K 680 could "walk all over" that VSSA (52V rails)!!
Reduce those 2 resistors to 56-68R on the CFA-X and the VSSA would
"squeak like a mouse" while the slewmonster roars at 140v p-p
geez ! He has the power ... but won't let it out
OS
PS - I not $$$ rich like y'all , My software is stolen , my PC's and trafos
are from the dumpsters (I do now have everything for 4 complete amps
still need heatsinks ).
Hopefully , by next Xmas ... i'll have a DIYA amp running all my new speakers.
OS
Hi OS, your not a thief, your a copyright infringer, this is a victimless crime IMO. Accepting monopolies as fair business practice is far more harmful than using software you would never buy.
I actually like recycling old gear, PCs especially. A good old Core 2 Duo can do anything a desktop needs
I had to print and scan it. Hopefully it is readable.
Edit; oops looks like BV beat me to it.
I looked over my IPS board and it looks like I can make it work. Cut 4 traces and install 3 jumpers and one resistor on the underside. I'll wait for OS to give it a go before I build one. Big thing is the front end in now running on full rail. The 12V CCS is gone so the devices all have to be rail worthy. Sure sims good though.
Blessings, Terry
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He's talking about dropping R7&R10 to 56-68R to increase the gain. I know this CFA-XH will stomp the VSSA once you get over 100w. I only tested up to unity input. It was very loud BTW. I,m not sure I want to drive my vintage JBLs too much harder. They're not rated for the power this amp can produce.
Blessings, Terry
My amplifiers have ground loop breaker circuits and the computer is galvanically isolated from the signal source. This, in general, keeps ground loops to a minimum, where if the galvanic isolation wasn't present the measurements would be screwed up (I know this because the isolator was put there specifically to break this loop).
Can you give a schematic?
I can't solve this problem .
Also i tried power the pc via UPS not connected to main outlet, but with the same results.