Yamaha Aventage RX-A1060 with VTV Purifi

[TheloniousEllington]

I bought a VTV Eigentakt EVAL-1 Purifi amp and connected it back in June to my Yamaha receiver and have used it 4-10 hours a week since. This last weekend my Yamaha decided to stop turning on without shutting off having "DC PRT 255 Zone 2" as the self diagnostic.

Would the VTV Purifi cause problems to the Yamaha receiver with the two being paired together?

Lastly, what solid state preamp would work synergistically and/or compatibly with the VTV EVAL-1 Purifi? Hopefully something with 3 inputs, but at least 2?

Thank you for your help and time.

 

[lovinthehd]

I'd say it's more an issue remaining with the Yamaha alone. Don't know what the diagnostic message is, have you contacted Yamaha for a translation?

Don't know what you mean about 3 inputs on a pre-amp? You have three different devices you want to connect to inputs on the pre-amp? Also, what's the budget? What was the old Yamaha receiver model?

 

[everettT]

I bought a VTV Eigentakt EVAL-1 Purifi amp and connected it back in June to my Yamaha receiver and have used it 4-10 hours a week since. This last weekend my Yamaha decided to stop turning on without shutting off having "DC PRT 255 Zone 2" as the self diagnostic.

Would the VTV Purifi cause problems to the Yamaha receiver with the two being paired together?

Lastly, what solid state preamp would work synergistically and/or compatibly with the VTV EVAL-1 Purifi? Hopefully something with 3 inputs, but at least 2?

Thank you for your help and time.

Seems that 255 is a location on the board that is causing the failure. Yamaha should be able to confirm.

 

[TheloniousEllington]

That's what I figured. It means either a leaky cap or dc voltage too high. Yamaha recommended a local repair shop that is authorized and they have to check it out.

I meant 3 stereo RCA channel inputs into the preamp.

 

[lovinthehd]

Does one of the three need to be a phono input?

 

[TheloniousEllington]

Does one of the three need to be a phono input?

yeah, but I do have a phono preamp for my turntable, so just another RCA input. Thanks.

 

[lovinthehd]

What should the pre-amp have in the way of features otherwise?

 

[TheloniousEllington]

Just a clean, transparent sound (I know it sounds cliche) and again compatible with the VTV Purifi amp. I don't need a sub output, surround sound or any options with effects; just clean and transparent. I hope that makes sense. Thanks again.

 

[lovinthehd]

So no tone controls, no dac, no dsp/eq? How about pre-amp output, is your VTV xlr input or rca? What's the input sensitivity of the VTV?

 

[TheloniousEllington]

Good questions. I don't need tone controls, dac or dsp, because I'll be only using it for my turntable/phono pre and from my interface TRS to RCA from my computer. The third would be for my phone jack to RCA.

My VTV has XLR input. That would be fine if it has XLR output, but I can deal with RCA to XLR, since that is what I was using for my Yamaha.

Sorry, I can't find the input sensitivity. I looked, but either missed it or can't find it. I checked the datasheet on the VTV website under description and on audio science review forum... https://vtvamplifier.com/product/vtv-amplifier-purifi-eigentakt-stereo-amplifier-based-on-eval-1/

 

[PENG]

Sorry, I can't find the input sensitivity. I looked, but either missed it or can't find it. I checked the datasheet on the VTV website under description and on audio science review forum... https://vtvamplifier.com/product/vtv-amplifier-purifi-eigentakt-stereo-amplifier-based-on-eval-1/

The gain of the Eigenkaft amp module is about 12.8 dB according to the datasheet that you can download from Purifi's website.

Sensitivity is a different thing as it depends on the output level, so it is always better to stick with gain rather than input sensitivity that, again depends on the output level that could vary quite a bit based on the load impedance the amp is driving, and the acceptable THD level as well.

If you order your Eigenkaft eval-1 from VTV, they offer different input buffers that will boost the gain high enough for most AVRs, that don't always have high enough output to drive power amps that has gain below 28-29 dB such as yours.

Assuming you order VTV's stock buffer, that is by Hypex, your amp will likely have about 25.5 to 26 dB of gain. To be reasonably conservative, let's assume 25.5 dB, then assuming you want to drive your amp to its rated output of about 200 W into 8 ohms, 400 W into 4 ohms, you will need about 2.1 V.

So then based on such assumption (200/400 W 8/4 ohms), you can say the input sensitivity is approx. 2.1 V.

Depends on how loud you listen to your music/movies, the typical mid range Yamaha AVRs won't have high enough voltage to take full advantage of your amp, but most people who listen to say 10 dB below reference level, sitting 10-12 ft from speakers with decent sensitivity such as 90 dB/2.83V/m, then you will be fine.

To be 100%, you can email VTV (Warren) and get him to confirm which input buffer you have in that amp. If you aske him about input sensitivity, they will likely tell you it is about 2 to 2.2 V if you in fact order it with their stock Hypex buffer.

 

[TheloniousEllington]

Warren just got back to me:

The Eval-1 is 2.5v to full power at 8 ohms. It is an easy load to drive and I haven’t heard of any problems powering it.

 

[TheloniousEllington]

To be 100%, you can email VTV (Warren) and get him to confirm which input buffer you have in that amp. If you aske him about input sensitivity, they will likely tell you it is about 2 to 2.2 V if you in fact order it with their stock Hypex buffer.

It's 2.5v to full power at 8 ohms. My Salk songbeat 3 encore speakers are 8 ohms.

I was looking at the Schiit Kara. Would that be compatible with the VTV Eigentakt EVAL-1?

 

[lovinthehd]

That Schiit Kara if it meets your other needs has great spec'd output (via ASR test) at 4V so that shouldn't be an issue....

 

[TheloniousEllington]

That Schiit Kara if it meets your other needs has great spec'd output (via ASR test) at 4V so that shouldn't be an issue....

Thanks, I appreciate it.

 

[PENG]

It's 2.5v to full power at 8 ohms. My Salk songbeat 3 encore speakers are 8 ohms.

I was looking at the Schiit Kara. Would that be compatible with the VTV Eigentakt EVAL-1?

Be careful with the term "full power", do we know what it is, I guess not!! If he told you 2.5 V, he must have based the amps rated output higher than I assumed. I assume that amp's rated output is just a little over 200 W, may be 220 W maximum, based on the datasheet. But hey, he sells them so that's reasonable for him to use a higher rating, such as at 1% THD instead of 0.1% that I typically prefer. By the way, Warren is a nice guy, a very experienced hobbyist himself but probably not too technically into the details, electrically speaking..

Take a look of the output vs THD graph on the datasheet:

At 1%, you do get quite a bit more than 200 W, but at 0.1%, it would actually be a little below 200 W.

That's why using input sensitivity is not as meaningful as using gain. With gain, you can calculate almost exactly why pre amp output voltage you need to drive your target power amp to the output level of your choice, based on your target acceptable distortion limit. With sensitivity, you often has to guess what the manufacturer's basis were when they published, or told you the specifications.

Regardless, this amp is an easy load only if you are using the balanced outputs of a preamp. For your Yamaha that only has unbalanced outputs, if you do need 200 W 8 ohm or more, then it isn't an easy load at all, because the Yamaha will struggle to even produce 1.6 V cleanly. However, if you don't listen loud, don't have speakers with low sensitivity, and don't sitting too far from the speakers, even 1 V will be good enough for you. So, it depends on your listening habit, speaker sensitivity, impedance, and distance a lot. There are less to consider, or worry, if the power amp's gain is higher, say 29 dB or more, but for the Purifi's 25 to 25.5 dB, you do have to consider the other factors I mentioned. It's a very transparent amp, so, time to enjoy the great clean sound, congrats to your purchase.

 

[TheloniousEllington]

Be careful with the term "full power", do we know what it is, I guess not!! If he told you 2.5 V, he must have based the amps rated output higher than I assumed. I assume that amp's rated output is just a little over 200 W, may be 220 W maximum, based on the datasheet. But hey, he sells them so that's reasonable for him to use a higher rating, such as at 1% THD instead of 0.1% that I typically prefer. By the way, Warren is a nice guy, a very experienced hobbyist himself but probably not too technically into the details, electrically speaking..

Take a look of the output vs THD graph on the datasheet:

At 1%, you do get quite a bit more than 200 W, but at 0.1%, it would actually be a little below 200 W.

That's why using input sensitivity is not as meaningful as using gain. With gain, you can calculate almost exactly why pre amp output voltage you need to drive your target power amp to the output level of your choice, based on your target acceptable distortion limit. With sensitivity, you often has to guess what the manufacturer's basis were when they published, or told you the specifications.

Regardless, this amp is an easy load only if you are using the balanced outputs of a preamp. For your Yamaha that only has unbalanced outputs, if you do need 200 W 8 ohm or more, then it isn't an easy load at all, because the Yamaha will struggle to even produce 1.6 V cleanly. However, if you don't listen loud, don't have speakers with low sensitivity, and don't sitting too far from the speakers, even 1 V will be good enough for you. So, it depends on your listening habit, speaker sensitivity, impedance, and distance a lot. There are less to consider, or worry, if the power amp's gain is higher, say 29 dB or more, but for the Purifi's 25 to 25.5 dB, you do have to consider the other factors I mentioned. It's a very transparent amp, so, time to enjoy the great clean sound, congrats to your purchase.

View attachment 64933

Thank you Peng for the details and factors with the VTV. I'm just beginning to get into these details with electrical measurements, schematics and data sheets. Some make sense in this case with listening levels for the unbalanced output to balanced voltage, but alot is fuzzy for me at this point in time.

For the Schiit Kara, Lovinthehd said the output is 4v. If that is going into the VTV eval1 which is 2.5v, wouldn't that be problematic that the voltage isn't matched? I believe he is right and knows what he is talking about, but understanding the details is confusing, since I'm new to these relations.

All in all, do you think the Kara is a good match for the VTV eval1?

Thanks again Peng for your time and help. I really appreciate it.

 

[PENG]

Thank you Peng for the details and factors with the VTV. I'm just beginning to get into these details with electrical measurements, schematics and data sheets. Some make sense in this case with listening levels for the unbalanced output to balanced voltage, but alot is fuzzy for me at this point in time.

For the Schiit Kara, Lovinthehd said the output is 4v. If that is going into the VTV eval1 which is 2.5v, wouldn't that be problematic that the voltage isn't matched? I believe he is right and knows what he is talking about, but understanding the details is confusing, since I'm new to these relations.

All in all, do you think the Kara is a good match for the VTV eval1?

Thanks again Peng for your time and help. I really appreciate it.

For preamps and amps higher output capability is almost always better. Don't worry about matching if it is between 5 and say 10 V balanced, it will work well with most power amps.