VSSA Through-Hole Version by Jason

[Bare]

Great thanks!
Yes Progress and I'm happy about it.
Fairly straightforward actually. Now that the Junk SMPS is gone

Gotta go and get some decent power connectors.
The Molex ones are proving as a V Bad idea.
So how do I buy a PS pcb (do I need 2?) and would you have a rudimentary parts List ..per chance (dilettante newbie here)

 

[jkuetemann]

I will have to put a list together. I tend to design for flexibility in parts choice and not dictate via a BOM. I will make note of anything 'special' and create a list sometime shortly.

Getting a PSU board will be the same as for the amplifier boards, a small PayPal transaction and I'll mail it out to you. You should only need one to serve the two channels. Unless you are really intent on one for each channel, but IMHO it is not required.

 

[still4given]

Hi Bare

Wow, I'm really surprised that the little SMPS wouldn't work for you. I have tested mine with a lot of different amps including this one, and was quite surprised how well it worked as long as I didn't push the volume too high. I don't have Jason's boards in a case so I can easily hook them up to different PSU's and see if there is an audible difference. This amp was designed with a +-36V supply in mind so the +-25V is a little low but I found it sufficient for normal listening. I have PMI's cap multiplier in the two PeeCeeBees I have in cases. I'm using 25-0-25vac transformers in those.

Blessings, Terry

 

[jkuetemann]

Bare,

Here is a rudimentary parts list for the CM PSU. Substitutions are possible, especially with the rectifier diodes, aluminum electrolytic capacitors and transistors. Should you have any questions don't hesitate to ask (ideally in the PSU thread). I hope this helps.

 

[Bare]

Still4: Yess.. Surprised me as well
Odd that it dumps soooo much energy into the pore lil VSSA pcb..
Yet meters Identically to the other 'still' functioning one.
Guessing(?) the meter doesn't present enough load to cause the thing to run wild.
You have one.. Any ideas what's failing?
No obviously damaged bits in/on it.
But then Im not knowing What to look for.. beyond Burnt.

Power? My Venerable Tannoys don't use much power being ~94db .
Likely 1 or 2 watts usage and the Lady of the house starts glowering, ~10/12 watts and the neighbors become restless, no idea what 50 watts would do.
Pitchforks possibly? Never tried.
However current delivery has proven important for realistic dynamics on these. Which was the rationale for Twin SMPS's.

Jason; Thank You !
Will PM you to get $ and paypal info.

Thinking that Jason's PS Gizmo at whatever the "normally'' used voltage is, will do Quite nicely.
No more second guessing. Clearly I'm not very good at it.

 

[Bare]

Still4: Yess.. Surprised me as well
Odd that it dumps soooo much energy into the pore lil VSSA pcb..
Yet meters Identically to the other 'still' functioning one.
Guessing(?) the meter doesn't present enough load to cause the thing to run wild.
You have one.. Any ideas what's failing?
No obviously damaged bits in/on it.
But then Im not knowing What to look for.. beyond Burnt.

Power? My Venerable Tannoys don't use much power being ~94db .
Likely 1 or 2 watts usage and the Lady of the house starts glowering, ~10/12 watts and the neighbors become restless, no idea what 50 watts would do.
Pitchforks possibly? Never tried.
However current delivery has proven important for realistic dynamics on these.

Jason; Thank You !
Will PM you to get $ and paypal info.

Thinking that Jason's PS Gizmo at whatever the "normally'' used voltage is, will do Quite nicely.
No more second guessing. Clearly I'm not very good at it.

 

[Bare]

Small update;
Issues with supplying power to My VSSA boards... thinking it was the poor choice of Power connectors.. switched to XLR versions.
Seems My ...second.. Chinee SMPS has failed.
This one can no longer supply power demands beyond the meter test leads.
Ohhh Joy ! Be sure to buy Chinese.. Kids

 

[e_fortier]

Hi,

I have completed 1 channel, one remaining. Will wait for both channels to work before listening.

Quick question; I'm having difficulty finding a decent 10uF as input cap. I'm looking for Polypropylene since it seems to be a better choice vs Polyester non-metalized or Polyester metalized (MKT).

I found a nice 1uF Polypropylene but it's a 1uF, not 10uF. http://www.digikey.ca/scripts/DkSearch/dksus.dll?Detail&itemSeq=176290258&uq=635729450723172972

Can I modify the circuit to use a 1uF ?

Am I worring to much...LOL...many people mentionned that Polypropylene is better than Polyester.

I have rarely seen 10uF as input cap, normally we see value like 2.2uF, the JLH (one of my fav.) uses 0.47uF

Thanks in advance.
Eric

 

[ivanlukic]

e_fortier,

Use the highest value cap you can find that has proper lead spacing. I prefer the sound of Polyester!

 

[Guitar.mod]

I found a nice 1uF Polypropylene but it's a 1uF, not 10uF.
<..>
Eric

Hi Eric.

Input cap and Rin (input impedance) form first order high pass filter.

If Your's amplifier has Rin = 22..47kOhm, You could use 1 uF Capacitor.

This version Rin = R2 = 10k

So You could try to rise it to 22 kOhm or look for larger capacitor.

p.s. 1 uF and 10 k forms High Pass RC filter of about 20Hz -3dB; maybe for Your loadspeakers it is enough.

 

[jkuetemann]

I think most are using MKT. I wouldn't stress too much about the type of capacitor, but some do.

 

[jwilhelm]

I think most are using MKT. I wouldn't stress too much about the type of capacitor, but some do.

10uF MKT are massive!

 

[jkuetemann]

Not as big as some types like polystyrene! I have Vishay Roderstein 10uF 100V MKT on all mine; the boards were built to have space for them.

 

[jwilhelm]

I just bought some Wimas without paying too much attention. 1.5'' centers on the pins.

 

[jkuetemann]

Wow, no kidding. I know some can be big but I figured 22.5mm (~0.900") LS was big enough. I believe the MKP is more compact. I got some 10uF 50V Wima in 5mm LS that work well in a reasonably sized package.

 

[meanman1964]

This is my VSSA version and my brother has test it in his recording studio.His opinion was strong tight bass,nice detail and noisless but compaired with his FetZilla compressed treble.Is there a way get rid of the compression.Maybe the bass is to strong compaired the treble.

Yesterday I had an amp/speaker shootout with an audio friend.
We compaired the VSSA with a Croft R7 amp(1900 Euro) and ques what non of the above probs.Treble,mids and bass all in balance.Verdict of my friend I like the VSSA over the Croft.Conclusion is made in his livingroom .The VSSA is a very good amp and realy deserve a nice casing.In my brothers recording studio the VSSA had to much bass or less mid and treble.At my friend place nice balance.Next thing for me to do use Jasons tweak but make it switchable.

 

[e_fortier]

I think most are using MKT. I wouldn't stress too much about the type of capacitor, but some do.

I don't stress about cap, I have a ACA amp camp that uses electrolytic as input cap (specific one chosen by NP) and it sounds fine.

Thanks Jason.

 

[still4given]

I was under the impression that the cap was there to keep out DC, not impart a sound.

 

[jkuetemann]

You are right, it allows DC blocking between the source and the input of the amplifier. It must pass the audio signal from the source to the amplifier input, which is why lots of folks stress over it. I've tried many types and I don't think there's any significant difference between them, but maybe my ears are made of tin .

 

[still4given]

Yes, I have bypassed them with no audible difference either. Maybe with a source with really high DC output may show up some audible difference, I'm not sure about that.