Measurement and Review of Berkeley Alpha DAC

[rebbiputzmaker]

I believe this is what you are referring to. If I recall correctly Mike Moffat feels the PCM63 was one of the best DAC chips ever made.

"Another rather unknown fact is the use of Burr Brown PCM63K DAC's. This is the only instance that these highly rated DAC's were used to incorporate 24 bit resolution. It is a special design by Keith Johnson who hand picked and tested for specific highest quality DAC chips and then used a technical tour d force design to allow for 24/88 on the PM HD1 and 24/192 on the PM HD2. I now use the HD2 as my reference DAC and it sounds better than any DAC
I have ever tested some approaching $30,000. "
https://reverb.com/item/8323569-pac...sor-rare-1-of-100-made-from-neil-young-studio

 

[FrantzM]

This Forum is a Godsend.. We, audiophile fall for price despite claims to the contrary .. On paper, the Topping seems to be as competent or even better than the BADA... Do we begin to realize how strong, sighted evaluation biases are? They are pervasive , insidious and very long lasting. We need the equivalent of a detox program . The ASR is more than a step in the right direction.

It would be interesting to establish some subjective impressions accompanying the measurements.

 

[rebbiputzmaker]

This Forum is a Godsent.. We, audiophile fall for price despite claims to the contrary .. On paper, the Topping seems to be as competent or even better than the BADA... Do we begin to realize how strong sighted evaluation biases are? They are pervasive , insidious and very long lasting. We need the equivalent of a detox program . The ASR is more than step in the right direction.

It would be interesting to establish some subjective impressions accompanying the measurements.

You last sentence is a good thought.

 

[stunta]

It would be interesting to establish some subjective impressions accompanying the measurements.

At this level, the only DACs I would be interested in subjective impressions of would be the ones that measure very poorly to see if there is an audible difference versus the DACs that measure well. Even this would just be a fun exercise as we are not really saving that much money with DACs that measure poorly - as Topping as shown, even a $120 DAC is very competent. I would be very surprised if someone can can pick out any difference between DACs that measure well in a DBT.

 

[Purité Audio]

Threshold of audibility is key, having said that I would still avoid sloppy engineering even if I can’t actully hear it.
Keith

 

[rebbiputzmaker]

Threshold of audibility is key, having said that I would still avoid sloppy engineering even if I can’t actully hear it.
Keith

What is sloppy engineering?

 

[Dialectic]

What is sloppy engineering?

For example, the kind of engineering that goes into Schiit products, as Amir's reviews have demonstrated. Because the performance parameters of a typical DAC are clearer than those of non-front-end components, it's somewhat easier to identify sloppiness in a DAC design than it is in, for instance, a speaker design, but sloppy speaker design is possible, too.

 

[Purité Audio]

A worst measuring ever loudspeaker ever thread might be fun, a break from the day to day schitt,
Keith

 

[Rene]

I believe this is what you are referring to. If I recall correctly Mike Moffat feels the PCM63 was one of the best DAC chips ever made.

"Another rather unknown fact is the use of Burr Brown PCM63K DAC's. This is the only instance that these highly rated DAC's were used to incorporate 24 bit resolution. It is a special design by Keith Johnson who hand picked and tested for specific highest quality DAC chips and then used a technical tour d force design to allow for 24/88 on the PM HD1 and 24/192 on the PM HD2. I now use the HD2 as my reference DAC and it sounds better than any DAC
I have ever tested some approaching $30,000. "
https://reverb.com/item/8323569-pac...sor-rare-1-of-100-made-from-neil-young-studio

The Model 1 used 20 bit dacs made by Ultra Analog. These were resistive ladder dac modules done using two-stage conversion. Each one was trimmed to true 20 bit performance by Pacific Microsonics engineers.
While the original breadboard HDCD converters used the Burr-Brown dacs, Keith felt they were not linear enough for the final product, and they were always going out of calibration when room temperature changed.
I agree that the Models 1 and 2 were and still are state of the art converters. I have not heard any better. They were the listening reference used when designing the Berkeley Alpha dac.

 

[Thomas savage]

A worst measuring ever loudspeaker ever thread might be fun, a break from the day to day schitt,
Keith

The animals at the zu love to play with their schiit....

 

[dallasjustice]

What is sloppy engineering?

Throughout your flawless track record as an audiophile, have you ever owned a product that you felt was poorly designed?

I know I have. I’ve made just about every mistake anyone could make. You must be lucky if you haven’t made a few mistakes over the years.

Engineering is the science of delivering a design at an acceptable cost the boss man believes potential customers will subjectively appreciate and buy.
My short list of things I personally haven’t appreciated over the years:

1. A custom class D linear PSU/hypex N core amp that blows up and shoots smoke everywhere in my listening room.
2. A DAC with a word clock that constantly drifts such that it’s impossible to use the DAC with active crossovers. I’ve had 2 of these.
3. An amp with an IEC input that can only work with a custom right angle/rotating power cord.
4. A loudspeaker with woofer copper leads so thin that they burned up when presented a log sweep from REW. And then waiting 3 months to get a new woofer I had to pay for.
5. An amp with a loose speaker terminal connection from a German manufacturer who wouldn’t fix it or even meaningfully help diagnose the problem. I had to get it repaired by a local tech.

If Amir can help free thinking people who work hard to earn the money they spend on audio gear to make a few better choices, I praise the King for his benevolence.

 

[Thomas savage]

All hail Amir the benevolent , our graceful and merciful lord your loyal subjects worship thy and are committed to following our gracious leader , our king and saviour ...,

 

[RayDunzl]

 

[Wombat]

You last sentence is a good thought.

Will you volunteer?

 

[rebbiputzmaker]

Throughout your flawless track record as an audiophile, have you ever owned a product that you felt was poorly designed?

I know I have. I’ve made just about every mistake anyone could make. You must be lucky if you haven’t made a few mistakes over the years.

Engineering is the science of delivering a design at an acceptable cost the boss man believes potential customers will subjectively appreciate and buy.
My short list of things I personally haven’t appreciated over the years:

1. A custom class D linear PSU/hypex N core amp that blows up and shoots smoke everywhere in my listening room.
2. A DAC with a word clock that constantly drifts such that it’s impossible to use the DAC with active crossovers. I’ve had 2 of these.
3. An amp with an IEC input that can only work with a custom right angle/rotating power cord.
4. A loudspeaker with woofer copper leads so thin that they burned up when presented a log sweep from REW. And then waiting 3 months to get a new woofer I had to pay for.
5. An amp with a loose speaker terminal connection from a German manufacturer who wouldn’t fix it or even meaningfully help diagnose the problem. I had to get it repaired by a local tech.

If Amir can help free thinking people who work hard to earn the money they spend on audio gear to make a few better choices, I praise the King for his benevolence.

Hi Michael,

It really is a pleasure to communicate with you as you're one of the few reasonable people here, Ray is another. There are some others but, let's just say a very different group at times. I have had a couple of those products also, but I've been a bit lucky I guess. Started building stuff as a teen, first speakers from Falcon Acoustics actually. Build a lot of electronics also. Learned a lot from some audio icons, it was always fun. Back then as a kid could not afford what I really wanted so did the next best thing and build it, or something as close as possible. Your answer is pretty reasonable but I don't think it necessarily applies what's this ongoing dac conversation. There are always armchair quarterbacks, who are quick to tell someone who actually is out there on the field what they're doing wrong. It's much safer that way I guess but doesn't always make it true. Yes Amir is trying to provide a noble service.

Best regards

 

[dallasjustice]

Hi Michael,

It really is a pleasure to communicate with you as you're one of the few reasonable people here, Ray is another. There are some others but, let's just say a very different group at times. I have had a couple of those products also, but I've been a bit lucky I guess. Started building stuff as a teen, first speakers from Falcon Acoustics actually. Build a lot of electronics also. Learned a lot from some audio icons, it was always fun. Back then as a kid could not afford what I really wanted so did the next best thing and build it, or something as close as possible. Your answer is pretty reasonable but I don't think it necessarily applies what's this ongoing dac conversation. There are always armchair quarterbacks, who are quick to tell someone who actually is out there on the field what they're doing wrong. It's much safer that way I guess but doesn't always make it true. Yes Amir is trying to provide a noble service.

Best regards

I think your background is perfect for a forum like this. If you stick around (and I hope you do), you’ll see that Amir doesn’t claim that his measurements are the final judgment for a particular product. I certainly don’t view them that way. Amir is providing some context and generating interesting conversation around how certain DACs are designed and how they compare to others. The intent is to inform and communicate to others interested in similar DACs. In the end, the decision to buy a product is 100% subjective and there are no manner of measurements that can change that. For some folks, the measurements Amir and others like BE provide likely influence subjective opinions. It’s true that defining good vs. bad engineering can be tricky. But the facts presented here aren’t presented on most any other fora. And very few manufacturers publish similar data. I bet that’s why you decided to sign up here. OTOH, I’m sure the measurements here don’t influence your buying decisions. However, I can say that many of the things I’ve learned about loudspeakers, DACs and amplifiers I’ve learned from the smart people in this forum or its predecessor.

IMO, audio and Music is an adventure. I take chances and do unusual things. I could have been ridiculed and drug into silly debates if I presented some of my ideas on other fora. Here it is different. For the most part, forum members are supportive and responsive to questions. I tend to listen to what people like Ray, Amir, Don, BE and a few other smart engineers have to say. They’ve changed my mind several times about bad ideas I’ve had and I thank them for that. That’s the value of this forum, IMO. I hope you stick around, participate, contribute and have the same experience.

 

[rebbiputzmaker]

For example, the kind of engineering that goes into Schiit products, as Amir's reviews have demonstrated. Because the performance parameters of a typical DAC are clearer than those of non-front-end components, it's somewhat easier to identify sloppiness in a DAC design than it is in, for instance, a speaker design, but sloppy speaker design is possible, too.

LOL lol

 

[Blumlein 88]

The animals at the zu love to play with their schiit....
View attachment 10667

Yeah read JA's Stereophile measures of Zu products and how he papers over the results.

 

[Jimster480]

While I imagine this review won't be popular like those of Schiit products (just due to audience size) this DAC actually measured really well considering its ~10 years old IIRC??
So if you bought this a decade ago and have listened to it every day since then you surely got your moneys worth!

Sure you can now replace it with a Topping DX7 but you had it for a decade already.... The other question is if its age has skewed its results. Surely some of the components on the inside will have exceeded their shelf lives? I know when I was ordering parts for my pMillet amp (that I never finished building) some of the caps and diodes were only set for 2000 hr lifespan?

 

[amirm]

While I imagine this review won't be popular like those of Schiit products (just due to audience size) this DAC actually measured really well considering its ~10 years old IIRC??
So if you bought this a decade ago and have listened to it every day since then you surely got your moneys worth!

Indeed it was my primary DAC in my listening system for good few months. The built-in volume control allowed it to run without a pre-amp which at the time was a difficult feature to find in DACs.