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New Amp to Replace Topping Pa5

raif71

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Since Topping Pa5 nuked itself and Topping probably can't guarentee a fix that won't have the amp failing in the same way again, I don't think I want to pay shipping to Topping to get it fixed. (This is a little sad given allegedly the cause for early failures was discovered.) Now I need a new amp. Setup is: Computer -> Motu M4 -> Topping Pa5 -> Ls50 Meta. Also have a Rythmik F12se sub connected to the Motu M4. The concern once again is noise. Ideally no noise could be heard with ear at tweeter but I can settle for inaudible noise at a very quiet room at 20in from tweeter if I feel like I must. Volume adjustment is done digitally. With pa5 due to the low gain, I felt noise was inaudible w/ ear at tweeter. (19db gain. I could turn my M4 all the way up past 5v output.) I live in US and I need everything in the chain to be balanced.

Options:
Buckeye Purifi: $1037 + $45 cables or $12 TRS->XLR Converter
Motu M4 caps out at 5.24v output so can't hit the spec for low gain but I assume that's ok given my low power requirements. 20.5dB/4.02Vrms (Medium), 15.5dB/7.16Vrms (Low). On bright side, 15.5db gain is good and Purifi is not known to have longevity issues despite being widely used. Anyways, since 19db gain was OK, 20.5 should also be OK. So this should be perfect ignoring cost.

Topping LA90 Discrete: $812
Buying from APOS so I don't have to send defective unit to China. 19.25db/2.2v high, 9.3db/7.3v low. This is like a cheaper Purifi in that noise can't be an issue. But it's Topping, so... uh... Well, at least original LA90 has been out for over a year without a thread of people complaining. This is the LA90 Discrete though.

Buckeye nc252MP: $545 + $45 cables or $12 TRS->XLR Converter
There is a chance I would want a preamp to fix the 25.5db gain which is too high. But what preamp would that be? I have a Mayflower o2+odac combo but I don't think it works as a preamp. Even w/ preamp, nc252MP should still be cheaper than Purifi. [-10db XLR attenuators also an option? $31 cost. Adds bulk and attenuates by fixed amount, but cheap and are unlikely to break.]

Topping Pa7: $465
I don't like this option. Linearity is a little suspicious. It's like a more expensive, less well-performing Pa5 that hopefully has Pa5 issues fixed. It's the cheapest though.

My assumption is if an amp's gain is low, the voltage the amp requires increases. If my M4 can't outfit high enough voltage, what happens is I don't get full max specced power from the amp but apart from that nothing funky/crazy happens. Another idea: Wait until Buckeye has a sale and live with 1 channel audio. I lived over a year with 1 channel, surely I can survive several more. ...right?

Most of the noise comes from dac due to gain of the amp, so if I can reduce gain somehow I believe this will reduce noise. If I can't have an amp w/ adjustable gain, then I think I can use a 2 channel preamp to functionally reduce the gain on a fixed gain amp. Noise comes from mains and not the sub. Volume knob on Motu M4 is digital and suboptimal. I want to keep that at max. If I have an amp w/ 25db gain and I want 15db, the idea is the preamp would functionally act as -10db gain and -10 + 25 = 15db. Correct me if I'm totally wrong. :)

Power requirements I assume are low. I still have no idea how to actually measure how loud my music is even with a calibrated mic. Years ago I used an A weighted cheapo SPL meter and got 70-75 at high end. I do have a sub. Let's assume 15-20db DR tracks? I think that is safe. 5-10db EQ headroom. Sitting up to 6ft away. LS50 Meta. I think even LA90 will suffice.

So: Which amp to get? If nc252mp and noise is audible, how to attenuate signal before it hits the amp? I don't need a headphone amp. Or... send Pa5 to china and pray Topping fixes it. (Some say after repair attempt it was fine, some say it broke again.) I'm going to need therapy if after going through noise-induced hell and jumping into a failing amp, the next amp breaks in 5 years. Is it unrealistic to expect 10yr operation?
So basically this unit is a pa5s ? :facepalm:
 

Doodski

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I'm thinking of white. Currently, amp and dac get put away on a shelf where they won't be visible. Slowly over a good number of years, I'd like to transform computer room into a white and pink room with some copper accents. Rose gold is my favorite color and that's not an option, but that's not a surprise. :D I think copper anodizing is cool too.
You always amaze me with the color coordination needs and sense of importance on the SNR and such.
I'm assuming it would be a bad idea for Buckeye nc252mp to be put in a close cabinet due to lack of airflow/heat?
The amps don't need free air for cooling although in a confined space the temp will increase until it reaches max temp based on available cooling and dissipation. If you stuff it in semi-confined space you could use a small fan for cooling and extend the life of it.

I'm not expert at the model numbers for Buckeye Amps but I think the Hypex NC502MP is the newer model? With better clamping of the PCB to the heatsink with the FETs and such clamped between the PCB and the heatsink plate. It is a major improvement. Have you considered the upgrade and get the better physical construction unit.
 
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BoredErica

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You always amaze me with the color coordination needs and sense of importance on the SNR and such.
:cool:
I think a lot about computers, SNR, and trying to build a nice room with a good mix of both aesthetics and good tech. I hope in the future to move my entire computer to another room and use an optic fiber cable for display. This will reduce coil whine concerns and reduce clutter in primary room.

The amps don't need free air for cooling although in a confined space the temp will increase until it reaches max temp based on available cooling and dissipation. If you stuff it in semi-confined space you could use a small fan for cooling and extend the life of it.

I'm not expert at the model numbers for Buckeye Amps but I think the Hypex NC502MP is the newer model? With better clamping of the PCB to the heatsink with the FETs and such clamped between the PCB and the heatsink plate. It is a major improvement. Have you considered the upgrade and get the better physical construction unit.

IMG_0133.jpg



IMG_0135.jpg

Hmm, I'm not sure what I'm looking at. :D I can make a post on their thread. I assumed construction would be the same, just different module/required changes. Price increase would be 26%. Purifi runs cooler though, right? The price increase would be more though.

A fan is possible if a lot of care is taken in making sure it's possible. It would introduce dust. I'm thinking nc252mp w/ white right now and hoping 5-7yr from now, Purifi-tier stuff would be ~$600 but I dunno how realistic that is at this rate.
 

Doodski

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I hope in the future to move my entire computer to another room and use an optic fiber cable for display.
Very nice!
Hmm, I'm not sure what I'm looking at. :D I can make a post on their thread. I assumed construction would be the same, just different module/required changes.
Check this image out. I marked the visible mounting screws so you can get an idea what the clamping is like on the newer model when compared to the older model.
zzzzz IMG_0133.jpg
 
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BoredErica

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I'm not expert at the model numbers for Buckeye Amps but I think the Hypex NC502MP is the newer model? With better clamping of the PCB to the heatsink with the FETs and such clamped between the PCB and the heatsink plate. It is a major improvement. Have you considered the upgrade and get the better physical construction unit.
I see that there are more screws for given area with the nc502mp.
Do you think the benefit goes beyond heatsinking? Perhaps less PCB flexing or something.
 

Sokel

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I see that there are more screws for given area with the nc502mp.
Do you think the benefit goes beyond heatsinking? Perhaps less PCB flexing or something.
Better than guessing I would wait a little if durability is your first concern (and I can understand why after your bitter experience).
Even though hypex has an excellent overall record and most importantly (the specific one) good after sale service too.

So,6 months?
(but I don't think it's necessary )
 

pjug

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Since the conversation is turning to reliability, maybe consider March Audio with the 5 year warranty. So similar to the the Buckeye purifi option. Downside is if you do have a problem you have to send it to Australia.
 

Doodski

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I see that there are more screws for given area with the nc502mp.
Do you think the benefit goes beyond heatsinking? Perhaps less PCB flexing or something.
I think both in that better clamping and less PCB flex is a big improvement.
 
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BoredErica

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I ended up w/ Buckeye NC252mp 2ch in white powder coat. Whether to get powder coat or not was a subject of debate because I'm not sure if the amp will ever actually be visible. I was drawing future plans for a large TV as a computer monitor, and the amp under the TV in the TV stand. The Motu M4 would have to be hidden because it's black, not that good looking, and has LCD screen I can't turn off. Also it has a XLR mic cable coming out front of it.

In that setup the Buckeye would be visible. But what if I put the Buckeye in a cabinet in the TV stand? Well, there are concerns about ventilation/heat. So I left it at that and decided to get the powder coat.

In retrospect, there are other options: Some TV stands have a hole cutout in the back, even for compartments with cabinets in them. This is also a hole that allows airflow if a slow fan is also in the cabinet. Or the hole in back could maybe even be made little larger with some DIY.

The ideal setup is the have PC in another room though this requires 45-50ft long cables. TV cable would have to be optic fiber, and USD hub would have to be powered. I'm not sure in such a setup if dac/amp should both be at the computer in another room with long speaker wire going to the speakers, or have the amp near the TV w/ long TRS->XLR cables instead. Or, have dac and amp by the TV and instead rely on the USB hub to carry the distance. If the amp's in the other room with the dac, well powder coat doesn't matter and I won't see it.

===
Wow, I dodged a bullet w/ LA90D it seems w/ the troubling reports of issues. Overall I feel like my decision to get Buckeye nc252mp was correct given the risk of noise could be solved with future preamp, DM7 upgrade, or signal attenuators.

I got these TRS to XLR cables off Amazon, 3.5ft $6 each. As cheap as possible. Probably garbage, but it's balanced and only 3.5ft long so I figure these would have to be ludicrously bad to have audible issues. They will do for now, methinks. After all, without knowing where the amp will be in the future, I don't know how long the cables would have to be.

Buckeye Impressions:
-Plugs to put banana plugs in in the back were quite tight for 2 of the connectors. I had to use a pretty decent amount of force to get them in all the way. Only frame of reference for me was the PA5, where it just went right in, I screwed it, and it was done. Suppose it's way better to be too tight than too loose though.

-Powder coat as far as I can tell so far seems flawless. No weird dents, inconsistencies, scratches, that I could find on cursory examination.

-Size was larger than I anticipated. Significantly larger than PA5!

-Power cable is kindda too short. I'm glad my amp was near the power strip.

-Front LED is way too bright. There is so much light output from the one LED (blue in operation) such that I can see the light bounce on my fridge 16ft away, my counter 10ft away. This is in an (attempted) dark room setup though. But I would argue people who want a dark room for movies and games are not that rare. Even with room lights on, I think the LED is distractingly bright if I had a TV stand and looked down slightly to see the light shining at me. I think LED indicators belong in the back (a la Rythmik, but that freakin' sub requires a DC offset blocker to not make me lose my mind with the noise which meant it had to be farther away from the wall meaning the light in back has more room to scatter) but I know most would disagree.

At very least I think basically all devices everywhere should have an option to turn off whatever LED there is. The LED pushes light out forwards, but lets some light into the case meaning I can see blue coming out of the vents on the top. It's enough to tell LED color even if the LED is taped over in the front. Tape better be well done, because what is the point of having a powder coat to look good if there's a dumb looking piece of tape in the front? I think with tape in the front the issue can be satisfactorily resolved, but it feels like an unnecessary problem.

I know people will think I'm crazy. The PA5 did this perfectly: The light is in the front, but it is very dim. It's visible if I go out of my way to find it, but otherwise it is invisible.

-Noise performance is an A-. Quite good, not perfect. I can hear noise with my ear 5in away from tweeter but it's not as bad as it sounds. I can only barely hear it. To be sure I'm hearing it I had to switch it on and off. At listening position there's no way I can hear it. Currently I consider noise a non-issue, and I'd rather address other sources of noise (getting a new fridge, moving the Comcast modem in the other room even further away because I can still hear it sometimes, etc.)

Noise is less than KH80 most likely and definitely better than 8030c I assume. My friend could not accept 8030c's noise and sold them for PA5 (lol) + Kef R3, and says they can hear noise ear 3in from tweeter, though they have more acute hearing than I. Overall nc252mp fails to meet my original stringent standards due to high gain, but still comes away looking good.

SUMMARY:
Good noise performance. LED too bright for dark room w/o correct setup or modifications. Good powder coat.

===
Also I just wanna add, that I find Topping to be the fast fashion of audio right now. There are stores like Forever21 that sell a ton of poorly made clothes with new styles all the time so people get FOMO and impulse buy because the stuff is cheap. When the stuff falls apart, they go for the next sale. Obviously Topping broke their own promise of taking special action if the replacement amp also fails (PA5), and there are troubling but not conclusive reports on LA90D side. PA7 is like a more poorly measuring PA5 and I don't think "we put less stuff under the black box to reduce heat" is good enough. Topping is not the only company that makes amps in any price bracket and Pa5 was not even their first product of its kind. Yet they are the ones with the longevity and even worse, customer service problems. The idea that "I can't guarentee it lasts 3 years, I don't even know if I will be here in 3 years" is disturbing. I understand not every company can be like Genelec, but 3 years is not a long time for a $400-800 product and I'm not going to buy a new amp every 3 years. Even purely out of greed, if I were in charge the Pa7 would be an oversized heatsink for extra $20-30 cost, and I will use that as PR for how much I listen to customers and want to make sure they are confident in their purchase.

Here's to hoping this terrible saga I've been through is finally at its end, and after yet another calibration I can actually focus on other things in my life. It's been so long since I heard music from left channel that it took a while for my brain to adjust. The amount of BS noise I've had to deal with, from sub DC offset hum, interference from the PC that got reduced but not removed with a new motherboard, to the PA5 causing noise and dying and then causing noise to the right channel, to the Comcast modem that manages to piss me off a room away, is overwhelming and it's been stressful dealing with all kinds of audio related issues with the setup I can't even think to name in here yet.
 
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001

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Since the conversation is turning to reliability, maybe consider March Audio with the 5 year warranty. So similar to the the Buckeye purifi option. Downside is if you do have a problem you have to send it to Australia.
Conversely, the 'upside' if you like, for me the March Audio is the preferred choice, anything else I would have to send to the USA. It's pretty nice when you find decent equipment in one's home country.
 

ampguy

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The many reports of hiss kills the nc252 for me, but I have a dead quiet pa5, a300 and many class AB amps. I just hope these cheap class d amps can make it to Black Friday, ideally 2024!
 

HoweSound

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I am listening to my new Hypex Nilai DIY 500 stereo power amp paired to a Schiit Freya S. Amp jumper set to medium gain. There is no discernible tweeter hiss. BTW the front LED on the HYPEX can be switched between high, low and off. After a week, feeling good about the choice to go with the DIY Hypex.
 
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BoredErica

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In a field that many consider pretty boring sonically (amps/dacs), whether people just say "nc252mp is same as Purifi", it's surprising people don't try to differentiate amps based on possibility of gain switch and dacs based on sinad. People say over and over again that sinad is pointless and comparing dac performance is the funniest waste of time ever. Imagine if instead I had gotten a 100... 90... sinad dac.

OFC one has to weigh extra cost of a Purifi over a nc252mp or DM7 + ADC over Motu M4 which evens the playing field vs buying a preamp, and as discussed in the past, attenuators are an option too. But I'd thought people would've focused more on noise.

People keep recommending Genelec 8030c but how many threads of people complaining about noise have there been? There's a new one from last week. My best friend sold their 8030c due to the hiss. (And if my friend's not hallucinating, even pa5 can be borderline w/ good hearing and that's not counting ultra efficient speakers.)

Audio is complicated enough as is. DIYing an amp is absolutely not for me. I'll DM Buckeye about the front led.
 
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Hipster Doofus

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Sorry to hear about all the issues folks have had.with the PA5.

I bought mine when it first came out and on sale I think. paid 349, in November of 2021. Hooked it up to my not too sensitive giant B&W 801s from 1979 with 12 in woofers. Played almost everyday with no problems. I have hooked them up using direct DAC to amp with the TRS cables and with a preamp, rca to balanced adapter . Never had an issue. It plays louder than I need it to play. I just recently upgraded to a PA7 because it has almost twice as much power . I think my speakers are 8 ohm. Could not hear any difference with the extra power. So, I am very satisfied with both purchases. Although I was expecting some bigger difference with the increased power Of the PA7.

PS bought a second PA5 for 299 in February 2023. With the inflation of the last 2 years I figured I really paid about 275. i just read of a $25000 dollar streamer on stereophile. The tax on that would be $2325.

RANDOM THOUGHT ON THE UNIVERSE……..
I am starting to believe we have reached a functioning level ( CANNOT TELL THE DIFFERENCE) of perfection in amplifiers, wether it’s a high rated Denon or an ultra rated Benchmark. So now I am focusing on room eq. And using any future funds to BUY BETTER SPEAKERS. At least with different speakers we ALL will have more to argue about. And isn’t that really what audio is really about.

IMG_0601.jpeg
 

ampguy

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Sorry to hear about all the issues folks have had.with the PA5.

I bought mine when it first came out and on sale I think. paid 349, in November of 2021. Hooked it up to my not too sensitive giant B&W 801s from 1979 with 12 in woofers. Played almost everyday with no problems. I have hooked them up using direct DAC to amp with the TRS cables and with a preamp, rca to balanced adapter . Never had an issue. It plays louder than I need it to play. I just recently upgraded to a PA7 because it has almost twice as much power . I think my speakers are 8 ohm. Could not hear any difference with the extra power. So, I am very satisfied with both purchases. Although I was expecting some bigger difference with the increased power Of the PA7.

PS bought a second PA5 for 299 in February 2023. With the inflation of the last 2 years I figured I really paid about 275. i just read of a $25000 dollar streamer on stereophile. The tax on that would be $2325.

RANDOM THOUGHT ON THE UNIVERSE……..
I am starting to believe we have reached a functioning level ( CANNOT TELL THE DIFFERENCE) of perfection in amplifiers, wether it’s a high rated Denon or an ultra rated Benchmark. So now I am focusing on room eq. And using any future funds to BUY BETTER SPEAKERS. At least with different speakers we ALL will have more to argue about. And isn’t that really what audio is really about.

View attachment 296285
I remember the 801s well! Never owned a pair, but listened to them whenever I could when they still had shops with listening rooms. I'm also enjoying the PA5, and in another thread here with a poll, half or more of users are not having issues, so we're not the only 2 users with working PA5s ... and whether we will have issues over time is not known, but certainly not a guaranteed thing that I'm aware of. Keeping the unit well ventilated, using balanced inputs as it was designed for, and using the knob on the amp at less than full on, may help to keep the amp running for a long time, or that is what I'm hoping for. I also hope the folks with issues get their work arounds resolved.
 

redjr

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It looks like Topping has a new version(s) of this amp. Wonder if it has the potting thing sorted out. Gotta believe they do. A lower power one the PA5 II for $249, and a higher power one, the PA5 II Plus for $329.

See them at APOS.
 
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BoredErica

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It's been a while now. Tell us : what did u do?
I contacted Topping. They were on holiday and finally back. Said if I can show the pa5 is broken (again), that I can get pa5 II provided I never had previous warranty action (I haven't). There are 2 issues here:

1. According to them, my email provider is blocking their email (gmail). So I sent them with outlook address and it worked. But that's a different email address I am sending from, and it lacks the email history where I already cleared that my amp is defective. So ok, I have to go re-record.
2. Pa5 has been on a shelf for months now so I reconnect it. And right now both channels work ok, which is the worst possibility because I know it's defective but it's working (for now).

So now I'm continuing to lose my mind over this. Before anyone starts to think that I've been pissed for 2 years over an incorrectly wired amp that was all my doing, an amp that has been wired doesn't just start hissing and then playing very loud popping noises and then ultimately die on one channel when left alone.
 
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JSmith

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Said if I can show the pa5 is broken (again), that I can get pa5 II provided I never had previous warranty action
This seems like the best option to me, as there are no major failure reports on the II as yet. In fact based on that I'm thinking of picking one up just to play around with and check out. I really think they should cover postage though...


JSmith
 
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BoredErica

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This seems like the best option to me, as there are no major failure reports on the II as yet. In fact based on that I'm thinking of picking one up just to play around with and check out. I really think they should cover postage though...


JSmith
I'm more than willing to pay for the postage. The fact that the pa5 is suddenly working on the broken channel again on reinstall is very troubling. With the way things have been going in this saga, I wouldn't be surprised if the channel dies again right outside of the warranty window.

I'm going to start using pa5 again until return window ends or the amp malfunctions. That's all I can do at this point.
 
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