in general, balanced arrangement of signal conditioning, results in nulling of all even harmonics, so result being dominant 3rd in THD Spectra
that's major difference, when speaking of sound, between non-balanced and balanced
of course, those are intrinsic characteristics of topology, one can spoil/ookoop anything if not careful or worthy
anyhow, one needs to be aware of own preferences and to pursue those
just one remark - my (as always - strong) opinion is that Balanced must be pursued all the way from source through amplification; amp itself doesn't need to be fully bridged (if there is no need or objective) but it must have proper balanced input (FE stage)
there are plethora of sources with balanced outputs, but inherently fully SE, having just some puny addendum glued to fabricate negative phase for XLR; those are not worthy of efforts
sole exception I'm aware of is PL phono stage (forgot which of older ones) being inherently SE, with discrete OP to produce neg for XLR
that's major difference, when speaking of sound, between non-balanced and balanced
of course, those are intrinsic characteristics of topology, one can spoil/ookoop anything if not careful or worthy
anyhow, one needs to be aware of own preferences and to pursue those
just one remark - my (as always - strong) opinion is that Balanced must be pursued all the way from source through amplification; amp itself doesn't need to be fully bridged (if there is no need or objective) but it must have proper balanced input (FE stage)
there are plethora of sources with balanced outputs, but inherently fully SE, having just some puny addendum glued to fabricate negative phase for XLR; those are not worthy of efforts
sole exception I'm aware of is PL phono stage (forgot which of older ones) being inherently SE, with discrete OP to produce neg for XLR
It is a few years away, but diya threads are known to last a long long time and who knows, you might beat me to it. One of the reasons for a true X version is that I want to drive my speakers properly balanced and with active XO. With the XA252 platform I will be able to and I believe in the architecture and the use of only two FETs in the output stage. Beyond SE, there is no other way to limit crossover distortion to its finest. I was going to build the GamuT D200i which also only use two power FETs per chn, but the engineer mentioned stability issues and comparing both schematics, the XA252 is a finer architecture. I do believe it is flying under the radar.
That is why I will compare unBAL and BAL before plunking down on multiple amp's
Can you give a link or some insight about this?
I’ve never had a good room for to put my speakers in and I have also my dream about building a house with it’s room for audio. Who knows if it will happen but just to have the info there 😁
Also congrats for your build, I have a similar amp to yours and what you describe is similar to what I heard on mine, only difference I don’t use global feedback and mine is bridged.
With mine I managed to get peaks of -/+20v(my dmm has a Crest function that gets the peaks each 1ms) into 4ohm(my speakers) which for me( actually for my neighbors)is a lot!
Happy listening and long live ZM!
Thank you. I agree, Zen Mod is the best!!!
So there are a few golden ratios. All of which are close to each other. This may be a good starting point:
http://www.cardas.com/room_setup_main.php
Here is another great resource. Anthony Grimani is a "Psycho Acoustician" as he likes to call himself. He has done a lot of webinars some of which I am sure touch on room dimensions. He designs high end home theaters and does presentations at CEDIA that companies pay to see. A lot of what he talks about applies to 2-channel as well. I suggest watching alot of his videos. It will give you a lot of insight on your from scratch build.
Anthony Grimani on Youtube
I recently moved into a new house. My listening 'space' is very close to the golden ratio. I have noticed a huge difference from my last house. Setup is much easier.
BTW, I pulled the preamp (BA2018) out of the circuit and ran straight from a topping D90 to the amp using my computer to attenuate the signal digitally. Wow! I wish I would have done that before writing my mini review. I am going to build a little passive preamp with a stepped attenuator that I have. The XA252 is like a kung fu fighter!
It just keeps getting better. My favorite amp
So there are a few golden ratios. All of which are close to each other. This may be a good starting point:
http://www.cardas.com/room_setup_main.php
Here is another great resource. Anthony Grimani is a "Psycho Acoustician" as he likes to call himself. He has done a lot of webinars some of which I am sure touch on room dimensions. He designs high end home theaters and does presentations at CEDIA that companies pay to see. A lot of what he talks about applies to 2-channel as well. I suggest watching alot of his videos. It will give you a lot of insight on your from scratch build.
Anthony Grimani on Youtube
I recently moved into a new house. My listening 'space' is very close to the golden ratio. I have noticed a huge difference from my last house. Setup is much easier.
BTW, I pulled the preamp (BA2018) out of the circuit and ran straight from a topping D90 to the amp using my computer to attenuate the signal digitally. Wow! I wish I would have done that before writing my mini review. I am going to build a little passive preamp with a stepped attenuator that I have. The XA252 is like a kung fu fighter!
It just keeps getting better. My favorite amp
Thanks for the info!
I don`t recommend using your computer to attenuate the signal, when you do that you attenuate only the signal, the noise remains the same. Just keep this in mind. Also at very high levels of attenuation the dac introduces some non linearities.
Best is to set the pc at -3db to -6db of attenuation(doing this the signal you get is no more bit perfect) this way you are sure the signal gets out unclipped and use the volume control on the preamp to do the attenuation.
With my amps I get 50-60uV of noise on the output with the preamp and dac connected and the volume adjusted for no attenuation.
If you can(if you have the gear) measure the thd with only the dac connected and also with the dac and preamp, you can see quickly the difference why you like one over the other.
I don`t recommend using your computer to attenuate the signal, when you do that you attenuate only the signal, the noise remains the same. Just keep this in mind. Also at very high levels of attenuation the dac introduces some non linearities.
Best is to set the pc at -3db to -6db of attenuation(doing this the signal you get is no more bit perfect) this way you are sure the signal gets out unclipped and use the volume control on the preamp to do the attenuation.
With my amps I get 50-60uV of noise on the output with the preamp and dac connected and the volume adjusted for no attenuation.
If you can(if you have the gear) measure the thd with only the dac connected and also with the dac and preamp, you can see quickly the difference why you like one over the other.
Attachments
Yes, the computer attenuating digitally is not optimal. The noise floor seems very very low. I plan on building a passive preamp as mentioned above. I am thinking, I have a salas in-select, and a Khozmo stepped attenuator. I have been wanting to have a single nice separate volume control for different lineages so this may be my excuse.
I realize that the BA2018 has THD, I just didn't realize how much of an influence it had on the clarity. With other amps, it was worth the sacrifice because the BA2018 has a nice sound. So a passive will get allow volume control while still being able to loop flavor in and out. The topping has enough gain to make your ears ring so that is a nice thing.
Now Zen just needs to design a square law DAC analog stage, a square law preamp, a square law phono stage, a square law muffin recipe, square law tires for my truck... Oh wait
I realize that the BA2018 has THD, I just didn't realize how much of an influence it had on the clarity. With other amps, it was worth the sacrifice because the BA2018 has a nice sound. So a passive will get allow volume control while still being able to loop flavor in and out. The topping has enough gain to make your ears ring so that is a nice thing.
Now Zen just needs to design a square law DAC analog stage, a square law preamp, a square law phono stage, a square law muffin recipe, square law tires for my truck... Oh wait
fastest and cheapest while still great bang for the buck - make Iron Pre, using Khozmo
if you don't need gain, that sans output autoformer
then try cheapest (you can find ) AVC, incorporated with Iron Pre - bridging regular pot pads, connecting AVC on output
you will not look back, ever
that's square law in preamp stage
if you don't need gain, that sans output autoformer
then try cheapest (you can find ) AVC, incorporated with Iron Pre - bridging regular pot pads, connecting AVC on output
you will not look back, ever
that's square law in preamp stage
it really depends ...... what sort of line stage you're going to use - how much Sugar you need in your system, ear/brain combo and foot BPM being judge of that
but, whatever line gain stage, my strong subjective stance ( as anything ZM is) is that inductive attenuators are superior to any type of resistive
and only when you hear properly implemented inductive one, you are able to realize how big obstacle resistive attenuators are
but, whatever line gain stage, my strong subjective stance ( as anything ZM is) is that inductive attenuators are superior to any type of resistive
and only when you hear properly implemented inductive one, you are able to realize how big obstacle resistive attenuators are
Right now the lack of sugar is pretty amazing. The amp is not detailed in a sharp edgy way which is why I think it works so well. I assume that has something to do with how you shaped the distortion characteristics of it.
So I'm going to look into your inductive preamp designs. Iron pre and pumpkin. The stepped attenuators that I have were a nice step up from the wiper type, like an Alps. So It would be even cooler to take it a step beyond that.
So I'm going to look into your inductive preamp designs. Iron pre and pumpkin. The stepped attenuators that I have were a nice step up from the wiper type, like an Alps. So It would be even cooler to take it a step beyond that.
Last edited:
exactly ...... I knew it is going to have plenty of zeros in THD figure, so invested all efforts to still have 2nd dominant, and major thing in first listening tests was exactly to determine how much it is differing to boring FiFi amps, with same stack of zeros and soul-less character, or even urging me to go outa room
anyhow, I was happy, rest is in front of you
though, this amp is 18 months old, now I must find some time to work on stack of several new pcbs .......
These are the actual aluminum plates that I used.
https://www.ebay.com/itm/334665495273
I have the third plate that I drilled the UMS pattern on. This means I could swap out the amp boards attached to the plates with something else very easily. The biggest advantage is that plate will have TO-247 mosfets on it which means I can mount them, solder them and not disturb them if I want to replace the boards with something different. Just leave them on the plate.
The bolts that hold the heat spreader plate to the heatsink bolt from the outside between the fins so no fumbling around inside the case with tools etc.
I plan on purchasing more of the plates so I can use them for whatever.
"Heat spreader next to MOSFET: 42.9"
"Outside heat sink: 42"
So the plate is between 42-42.9 depending on where you measure with ambiant being 16.9.
https://www.ebay.com/itm/334665495273
I have the third plate that I drilled the UMS pattern on. This means I could swap out the amp boards attached to the plates with something else very easily. The biggest advantage is that plate will have TO-247 mosfets on it which means I can mount them, solder them and not disturb them if I want to replace the boards with something different. Just leave them on the plate.
The bolts that hold the heat spreader plate to the heatsink bolt from the outside between the fins so no fumbling around inside the case with tools etc.
I plan on purchasing more of the plates so I can use them for whatever.
"Heat spreader next to MOSFET: 42.9"
"Outside heat sink: 42"
So the plate is between 42-42.9 depending on where you measure with ambiant being 16.9.