Going diy this family one is free to build the various other VSSA threads which author helped allot, build it as one like with tuneup/specs/stability and documentation work on own shoulders.
Building GB VSSA (obsolete) or First One, one gets tuneup/specs/stability and documentation by paying very fair cost.
Else you right and question can sneak in how a specific recording should sound in reality, but given thread is in commercial sector marketing seems a right/fair.
Do I hear bring VSSA back to life?
Don't ask me.This line written with invincible fonts.....maybe try a smaller batch as start.....and maybe a never v1.5 (see post 3252).....
This line written with invincible fonts.....maybe try a smaller batch as start.....and maybe a never v1.5 (see post 3252).....
Same as Ricky, VSSA is for no doubt a good competitor and will suit many poeple. Despite my versatil way, VSSA/SMSP300RE will take place in nice little. Nor the sound quality what's is fun with VSSA is the small size of final combo...
Marc
We found some time in today's listening session also to put VSSA next to the First One just for the curiosity how it will perform. In a form like it is VSSA doesn't stand a chance to beat its bigger brother.
We tested VSSA (2xSMPS400 modified caps) and First One (2xSMPS1200 stock) at my place on my hard to drive Thiel speakers.
I agree with Lazy Cat that First One dual mono beats VSSA dual mono configuration in all aspects. Is the difference huge? I would say normally you would pay double or more to get the same difference in the hi-fi shop.
Still I believe that VSSA on its own (not in comparison) is very good amp. There was definite sound improvement when we lifted the ground wire going from amp pcb to the chassis ground. Same improvement goes to FO when executed.
I believe different earthing arrangement has to be done to get optimal sound quality.
Do I hear bring VSSA back to life?
Hehe, maybe you should. I heard there were some improvements that made First One so transparent compared to VSSA 1.4. Maybe you could easily adapt them to the new VSSA2.0 project.
Also we could try SMPS1200A180 for supplying the power.
Do I hear bring VSSA back to life?
VSSA will never die
IMHO, given the small PCB size, it is a splendid candidate for bridged amplifier.
Dear LC, if you are considering a new GB, please consider a PCB that could be built as bridged amp or split into dual mono. That would be a nice feature.
I will make the bridged version from scratch myself as time allows but it will end as a big PCB, in my case...
Gratefuly yours,
M.
Thanks for info, taking a lazy angel to spare some maybe wasted work and for curiosity/knowledge, is there possibility if details/schematic or principle for optimizing/tweaking groundings could be shared some time.
There are some ideas in the background how to proceed and also evaluate the possible change in sound. The amp board itself (FirstOne and VSSA) are both optimized in a way that no hum is audible, which speaks for itself for very good star ground PCB layout.
Where we could find further improvement is how theAMP PCB ground is connected to the case and through this connection it can "see" the other AMP PCB ground. When this ground connection was lifted, the PCB modules stopped interacting with each other and more clear sound was immediately apparent, with completely precise instrument positioning in the whole spectrum. There were no sonic downsides, only improvements.
There is an electrical disadvantage. Modules and power supplies are no longer DC grounded and that can be a potential threat for electrocution.
Solution would be a graetz bridge or 2 opposing diodes with a 1 or 2.2 kOhm resistor in parallel, and altogether in series with the ground wire.The resistor would keep the potential at ground level, in case of failure the power diodes would take over. But as I said we haven't tried it yet due to lack of time.
hose4 big thanks for revealing solution to tested sonic improvements, diy'ers always hungry for such.
Understand some progress on safety is going to be tested later.
(Info to last and mayby just to be ignored: I do not want to be wise guy and skeptic and in reality at present don't have the knowledge, but thinks somewhere VSSA or FO thread it was mentioned that the ESP trick you probably also know of and maybe same as the one you described ain't good for SMPS)
Understand some progress on safety is going to be tested later.
(Info to last and mayby just to be ignored: I do not want to be wise guy and skeptic and in reality at present don't have the knowledge, but thinks somewhere VSSA or FO thread it was mentioned that the ESP trick you probably also know of and maybe same as the one you described ain't good for SMPS)
yes, was mentioned by Esperado as a reply on my suggestion, and it is true that the problem with SMPS is that the GND potential might be at VAC / 2 due to some Y cap for filtering EMI... for that reason, if you put a resistor between 0V and earth, you see some little voltage like few milivots across the resistor due to the VAC flowing trough it via some 1nf or 2nf capacitor. Then this few mv might come as a noise ... so probably a tradeoff is needed
The ESP trick was mentioned in First One post number 707. When you click on the link, look for ESP ground breaker.
As mentioned in previous post there is a chance of some noise coming back to the audio circuits. Based on impendance of this ground loop the noise should be fairly low. But it is hard to say without trying.
Original config was left_PS - left_amp - chassis_ground - right_amp - right_PS. At the moment the config is left_PS - left_amp and right_amp - right_PS both floating for DC.
The idea is to use ground wire from left/right_PS via resistor and diodes to ground. Testing can be done via switches. So changing the configuration can be easy.
hose4,
My question would be if the ground loop problem would be lessened if you only had one common power supply rather than two independent supplies with the extra ground loop potential?
The second question is how do you determine the diode values and the resistor values in that circuit put up earlier to break the ground loop?
My question would be if the ground loop problem would be lessened if you only had one common power supply rather than two independent supplies with the extra ground loop potential?
The second question is how do you determine the diode values and the resistor values in that circuit put up earlier to break the ground loop?
(thousands of postings this thread
) Thanks for reminding and further for summing up details me/others to learn from.Agree and most time very polite/humble and helpsome (Temperament and sensitive, teaser Christophe
keep clear of moderator radar else going read only mode). I made his suggested dampening for speaker drivers earlier this thread by linearizing impedance by resonance filter + zobel filter and for me did huge sonic improvement. Thanks very interesting and smart with switches, good investigation.
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Brytt,
Yes Christophe has only confirmed what I have learned about using conjugate networks on the speakers themselves to correct the impedance curve of loudspeakers. I have been in complete agreement with him on this point though others seem to disregard the facts. You can point people in the right direction but that doesn't mean they want to go there!
Yes Christophe has only confirmed what I have learned about using conjugate networks on the speakers themselves to correct the impedance curve of loudspeakers. I have been in complete agreement with him on this point though others seem to disregard the facts. You can point people in the right direction but that doesn't mean they want to go there!
Or maybe out there some not interested in sharing/spread what suggested like in a movie.
Later on a thought hit me that the impedance filters shall have a try on a dynamic microphone. Have some cheap Behringer mics where a direct live compare between same models, one without correction and the other with correction should be possible hooked up on a mixer. Only bump is value for inductor gets huge but fortunately power value is minimal.
Brytt,
That will be interesting to see what it does to the frequency response of that mic. In a loudspeaker I have a good idea but I don't really study microphones on that level that I have looked at the impedance curves. I imagine that the Behringer mic is a plastic diaphragm so make sure that the tests are done under the same atmospheric conditions as that will change the response curve on that type of diaphragm. Temperature and humidity are critical to a test of that type of microphone.
That will be interesting to see what it does to the frequency response of that mic. In a loudspeaker I have a good idea but I don't really study microphones on that level that I have looked at the impedance curves. I imagine that the Behringer mic is a plastic diaphragm so make sure that the tests are done under the same atmospheric conditions as that will change the response curve on that type of diaphragm. Temperature and humidity are critical to a test of that type of microphone.
I have a DATS unit with which i tested the mic therefor can report impedance curve looks exactly as a full range speaker just the resistence is much higher. High resistence the correction inductor gets huge in value for the resonance filter. My speakers get more resolution and precision with the correction filters, this i would love transferred to a mic, and maybe the preamp will like it too
. In sim it linearize group delay, maybe this can be transferred to better precision and resolution (freq spectre of interest fires same time). If it hurt frequency response a counter EQ could be added. Your advise temperature/humidity didn't know, will remember.
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