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VTV Purifi 1ET400A updates

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Hi, wich is the volume level number on your smsl su-9 at max power of the VTV purifi ampli (xlr connected)?
Thanks G
Hi mate - for 'normal music' it is at volume levels between 20-30 on the SU-9 (XLR out). However, for silent recordings, there are times where I need to bring it up to 80. I then need to be very careful that I bring it back down to 20 before the next track starts hah!

I contemplated bypassing the gain in the Purifi amp, however I will just keep it here and implement stringent volume control to make sure I never blow anything hah.
 
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Hi mate - for 'normal music' it is at volume levels between 20-30 on the SU-9 (XLR out). However, for silent recordings, there are times where I need to bring it up to 80. I then need to be very careful that I bring it back down to 20 before the next track starts hah!

I contemplated bypassing the gain in the Purifi amp, however I will just keep it here and implement stringent volume control to make sure I never blow anything hah.
For this reason I'm planning to buy a buffer with 4,5/5 volt input for getting max output (about 7db) so the total Gain could be 7+12,8=20 Infact max output in the smsl su-9 is about 5volt. Buffers with this kind of "mid" gain are those on Audiophonics et400, Vtv Et400 and customizables like on March Audio. I ask to everyone if i'm missing someone else.....
 
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Does anyone have experience in standard mode vs. low-gain mode? Does the low gain mode have audible benefits?
I tried with my VTV Eval1 amplifier today with SMSL SU-8 v2 dac. The DAC is set to volume 14 (max is 40) in standard mode, and around 23 to have similar volume for low gain. So there's no headroom problems.
But it sounds more mellow and boomy in low-gain mode.
But again, i have no idea if this is placebo or if it has any real audible benefits.
 
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Can someone explain to me the difference between the 10k input impedence on the stock purifi input buffer and the 47k input impedence on the hypex input buffer. I don't understand which one to get and they're around the same price point.
 

nimar

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I'm in conversation with VTV now. I will ask if they can sell an amp without the mains filter.
I asked Warren about the inlet and he wasn't very receptive to the idea. It seemed he doesn't believe the Y capacitor is a problem. While I think VTV offers a great service, and he was very accommodating and responsive, at the end of the day I'm going to side with the designer (Bruno) rather than a manufacturer about the technical merits / considerations of a particular component to work with the designer's system.
 

Rottmannash

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I asked Warren about the inlet and he wasn't very receptive to the idea. It seemed he doesn't believe the Y capacitor is a problem. While I think VTV offers a great service, and he was very accommodating and responsive, at the end of the day I'm going to side with the designer (Bruno) rather than a manufacturer about the technical merits / considerations of a particular component to work with the designer's system.
I have the VTV Eval 1amp and have had no issues with it. If there are problems with these caps I can't audibly detect it.
 

nimar

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I have the VTV Eval 1amp and have had no issues with it. If there are problems with these caps I can't audibly detect it.
Totally. Not suggesting anyone go and throw out their amps because their inlet has Y capacitors, but it can introduce ground noise into the system. The Ghent inlet was <$5 and since I had already built one, I wanted them to be exactly the same. Perhaps you are just lucky and don't have an issue with a noisy ground, or perhaps it would never be audible.

Also because I didn't like the cables being rammed into the heatsink/case, I also flipped the PSU around so it faces the front like the original Eval1 build from Purifi. Warren's logic was it provided shielding, but I'd rather have the heatsink away from the amps, and Amir tested it in that config with stellar numbers so maybe there is no need for the shielding.
 

Rottmannash

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Totally. Not suggesting anyone go and throw out their amps because their inlet has Y capacitors, but it can introduce ground noise into the system. The Ghent inlet was <$5 and since I had already built one, I wanted them to be exactly the same. Perhaps you are just lucky and don't have an issue with a noisy ground, or perhaps it would never be audible.

Also because I didn't like the cables being rammed into the heatsink/case, I also flipped the PSU around so it faces the front like the original Eval1 build from Purifi. Warren's logic was it provided shielding, but I'd rather have the heatsink away from the amps, and Amir tested it in that config with stellar numbers so maybe there is no need for the shielding.
That was my next question but I believe you've already answered it. What are the possibly negative consequences of having Y caps in the inlet?
 

carneb

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For those of you who purchased the VTV Eval1 amp, did anyone option the 12V trigger?

I'm interested to know how the trigger input interacts with the on/standby switch. I assume that if the switch is in the standby position then the amp will only operate with a 12V trigger signal, and with the switch in the on position the amp will operate even without a 12V trigger signal.

Can anyone confirm this?
 

Rottmannash

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For those of you who purchased the VTV Eval1 amp, did anyone option the 12V trigger?

I'm interested to know how the trigger input interacts with the on/standby switch. I assume that if the switch is in the standby position then the amp will only operate with a 12V trigger signal, and with the switch in the on position the amp will operate even without a 12V trigger signal.

Can anyone confirm this?
Nope. That's what I thought as well. I emailed Warren and he said the stand by switch is there for testing purposes only and to leave the switch to on. The 12V trigger works as advertised.
 
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Hi All,
FIRST POST! I'm looking at the VTV 5 channel amp (3 ch Purifi with the 2 ch hypex 252). However, my current AVR only has unbalanced outs. I've had a pretty frusterating experience with my Crown XLS 2002 to a DIY sub where I got almost no output until I put an ART Cleanbox to really boost the gain (the .775 inputs on the Crown don't work as intended). So for Sub duty, I think the CleanBox is fine but no way am I putting it on anything about 100Hz (i.e. my LCR)

Would an unbalanced out from the AVR to a balanced in on the amp result in the same massive requirement for gain compensation? If so, how should I approach using a balanced amp in an AVR with unbalanced outputs? I like that the Nord has an unbalanced/balanced switch but it's fairly expensive and doesn't have the purifi 5 channel option.
Thanks,
TJ
 

Rottmannash

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That's disappointing. Thanks for the feedback
Why is that disappointing? The amp works as advertised. Either on all the time w/o a 12V cable inserted or off when a 12V trigger cable is inserted. Or one could switch it to standby and it would never turn on.
 

carneb

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Why is that disappointing? The amp works as advertised. Either on all the time w/o a 12V cable inserted or off when a 12V trigger cable is inserted. Or one could switch it to standby and it would never turn on.
Just disappointing because if it worked the way I thought it would then it would have suited the ways I want to use it
 
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