Twisted Pear Audio - Buffalo32S (ES9018 DAC)

[leo]

Leo,
thanks for checking, looks almost identical, frequency ca 20k; your oscillations amplitude seems to be even bigger comparing to main signal.

I always thought the pre and post ringing is caused by the type of OS filter, this square wave actually looks a lot like the output of a PCM1794 based dac I once had

 

[leo]

Ahh - more psychological phenomena misinterpreted as physical phenomena. Pretty much what I thought.

Perhaps the people describing the Buffalo 32s as "dull" are simply registering an absence of the (pleasing?) distortion that they had grown accustomed to from other, less accurate DACs?
Food for thought...

You could be right, I personally can't stand HF distortion or the fake bright sound you get with a lot of digital sources, I've noticed with a lot of gear it can become too much with complex music.
I still think its worth experimenting with alternative regulation for at least the IVYII stage, I'm finding things much more effortless now

As already mentioned I'm happy with the sound at the moment anyway, I've had a few mails from folks though with this dac and they seem to think it sounds overly smooth
I wonder how many of those have valve amps

 

[AlanElsdon]

You could be right, I personally can't stand HF distortion or the fake bright sound you get with a lot of digital sources, I've noticed with a lot of gear it can become too much with complex music.
I still think its worth experimenting with alternative regulation for at least the IVYII stage, I'm finding things much more effortless now

As already mentioned I'm happy with the sound at the moment anyway, I've had a few mails from folks though with this dac and they seem to think it sounds overly smooth
I wonder how many of those have valve amps

Leo,

I am a vinyl junkie and only came into the digital domain in a big way last year building a cMP2 computer; I cannot stand HF problems and for a few years hated CD players. But with this combination of cMP2 and the Buffalo32 I have to say that it sounds like my vinyl system used to - or at least how I remember it, so I will be dragging it out over the weekend to have a listen.

I love the presentation of the Buffalo - highs sound natural (just listening to some Blue Note CD's) - absolutely beautiful.

Not sure if I have posted the system but just to put my comments in context:-

cMP2 with Juli@ modified for SPDIF output; Buffalo32 using SPDIF psu's are TP's mono versions; Lightspeed Attenuator; Peter Daniels Patek-style amp; Gedlee Abbey speakers.

All of these are what I would describe as open/transparent and they do not seem to exagerate any frequencies.

One other thing about the Buffalo is that listening at lowish levels is still very nice.

 

[krgaunt]

Dull sounding music

I belive a lot of the sound quality comes from the recording, and the Sabre/Buffalo just brings out whatever is on the recording. Nothing seems to be added or subracted by the Buffalo/Sabre. Music that has a large amount of signal processing or that's recorded poorly really stands out as being 'dull' when played through the Buffalo. Lots of recordings of great singers, Streisand for example, don't bring out the fullness of the singer's voice. One Streisand anthology CD that I've listend to only contained a couple recordings that really brought out her voice. I've heard dull recordings of many orchestras as well.

I've found live recordings, or well made recordings (Chesky Records for example) sound fantastic and very alive through the Buffalo.

I meet with some friends from time to time to play recordings that sound amazing. Am I the only one with a Buffalo that's now going around trying to find amazing sounding recordings?

RossG

 

[Russ White]

Hi Leo,

I don't have any problem with your suggestions. I am just stating what I believe to be true.

I get PMs too.

I actually very much appreciate your good will and intentions.

Cheers!
Russ

 

[Russ White]

Leo, it looks from your 1khz square wave scope shot that ESS my well have change the OSF from the ES9008 to the ES9018.

If Dustin if watching the thread maybe he will chime in.

 

[Russ White]

So, for those of you who are wondering. I have not forgot about the "Placid" shunt regulator I started working on about a year ago. I have just been perfecting it.

Here is a simulated FFT of line regulation with input 15V and a 1V sine wave on the input voltage. The output is 3.3V with a supply current of 200ma and a load of 100ma.

I will know very soon if the real thing works.

As you can see. The PSRR is excellent if the sim is even somehwat close to right.

So for those of you wanting something other than LM317/337. This should be the ticket.

Cheers!
Russ

 

[Jean-Charles]

So, for those of you who are wondering. I have not forgot about the "Placid" shunt regulator I started working on about a year ago. I have just been perfecting it.

Here is a simulated FFT of line regulation with input 15V and a 1V sine wave on the input voltage. The output is 3.3V with a supply current of 200ma and a load of 100ma.

I will know very soon if the real thing works.

As you can see. The PSRR is excellent if the sim is even somehwat close to right.

So for those of you wanting something other than LM317/337. This should be the ticket.

Cheers!
Russ

Good news Russ. I was just wondering.
What will the output imprdance look like?

 

[Russ White]

Good news Russ. I was just wondering.
What will the output imprdance look like?

I was hoping you would see this.

Here is the output impedance.

Same voltages and current/load as before.

It does equally well at higher voltages btw. Up to 20V or so should be fine.

The solid line is the impednace. The dashed line is phase.

So it practically nothing. The trace/wire impedance will dominate.

 

[tailspn]

Looks great!

Do you have any idea of the board size yet? Will it be single regulator boards, or bipolar? And if it is not a complete power supply(s), can it use the LCDPS and LCBPS as preregs and rectifiers?

Thanks,
Tom

 

[slartibartfasst]

Hi Russ,

Are you using the LME chips on the Placid?

Edit:

What frequency range is most important, frequency and phase-wise, for the Sabre/Buffalo32S?

Thanks,
Slarti

 

[Russ White]

At any frequency above 1mhz the regulator (any regulator) load regulation will start to fall off dramatically. This is where bypass caps come into play.

The placid will be all through hole. With a DIP opamp. So you can use a multitude of opamps. We will likely supply LME or similar.

The power devices are TO220 full pack type and will be well heat sinked. You ought to be able to get 200ma out of each supply easily. The output current and voltage will both be adjustable.

The first iteration of the circuit will likely be a single supply. But you could easily connect two in series to get a bipolar supply.

Later I will likely do a bipolar version.

:EDIT:
I will also put a rectifier and caps on the board so you can use it directly. If you want to use a pre-regulator that is fine, too. But the line regulation is so good I can't see any reason to need to.

Cheers!
Russ [/B][/QUOTE]

 

[TheShaman]

That's good news, Russ! Was hoping you wouldn't give up on Placid..

Any idea what kind of voltage drop will be required for the Placid to work properly?
I hope I can keep my current transformers..
They are spec'ed at 2x18V AC for IVYIIs and 2x12V AC for VD, a bit higher than the 2x15 and 2x9 recommended, having shunt regulators in mind.

 

[Russ White]

The placid should work fine from 5V to 20VAC transformers. I will know better once I have really tested it.

The lowest practical output is 3.3V. The highest is about 25V.

Current through the CCS can be adjusted by the user and safe operation will require appropriate setup.

I will start a dedicated thread at some point.

BTW noise should be very nice and low.

The voltage reference is an LED with RC filter, and it is supplied by the regulated voltage and a CCS to make it even more clean.

Cheers!
Russ

 

[hybride]

off topic; I have a broken buffalo 1.0 and Emailed several times to questions@twistedpairaudio.com to ask where to send it back for repair.
I get no answer anymore? Why? (hanssatink(at)gmail.com)

 

[brgds]

brgds,

Sorry if I can't be much more help. I suspect there is something else at work.

Cheers!
Russ

Russ, you were perfectly right. I’m more than happy to advise that my BUF finally started to sound as I expected – after a week of burning of the whole system, and it’s improving from day to day. I suppose I know what happened … but that would be very much OT.
The most impressive and new things are: bass – deep, well controlled, springy and rich; overall resolution; scene depth; liquidity. The only concern is a bit thin middle band with a kind of ringing on higher midds which make sometimes piano or female voice unnatural and “jazzy”. Hope that’ll disappear soon. Perhaps I should enable those 22Ohm series resistors?

 

[Russ White]

Perhaps I should enable those 22Ohm series resistors?

Absolutely you should.

 

[poseidonsvoice]

This recent review at 6moons of the Peachtree Audio Nova convinces me even more that the Sabre based dacs are the way to go. Give it a read. I've only included it here because both of these companies are based on fruits

Peachtree
Twisted Pear

Best,
Anand.

 

[leo]

Hi Leo,

I don't have any problem with your suggestions. I am just stating what I believe to be true.

I get PMs too.

I actually very much appreciate your good will and intentions.

Cheers!
Russ

Thanks Russ!

I've been using it with the headphone amp the last few days, next step I think is to get a volumite , convert the cans to balanced and ditch the headphone amp

 

[leo]

This recent review at 6moons of the Peachtree Audio Nova convinces me even more that the Sabre based dacs are the way to go. Give it a read. I've only included it here because both of these companies are based on fruits

Peachtree
Twisted Pear

Best,
Anand.

Interesting, doesn't their stuff use the ESS 9006 though