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Old 2nd July 2012, 01:19 PM   #361
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Quote:
Originally Posted by GaryB View Post
It's similar to the buffer that Joachim Gerhard suggested in this ES9022 thread Anybody using the new ESS Vout DAC (ES9022)?

---Gary
The link to the post showed two schematics and naughtily I sort of added/ameded one a bit... hope nobody is offended. This is basically a solid state version of our Super Linear Cathode Follower, so we can call it a Super Linear Fet Follower.

Cheers, Joe
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Last edited by Joe Rasmussen; 2nd July 2012 at 01:31 PM.
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Old 2nd July 2012, 01:45 PM   #362
GaryB is offline GaryB  United States
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Quote:
Originally Posted by Joe Rasmussen View Post
The link to the post showed two schematics and naughtily I sort of added/ameded one a bit... hope nobody is offended. This is basically a solid state version of our Super Linear Cathode Follower, so we can call it a Super Linear Fet Follower.

Cheers, Joe
Joe,
Any comments on the benefits of the SLCF compared to the simple cascoded source follower circuit that I use? This is the 2nd transformer output Buffalo DAC that I've built. The first one used 1:1 transformers and a bipolar diamond output buffer. And it was based on the original ES9008 Buffalo kit with simpler power supplies. This new version has better supplies, newer ESS chip, low value resistive loading to ground (thanks Joe), step up transformers, and the FET buffer. It sounds much "fuller" than the first version. Both have great detail but the first one was a bit lacking in body. This version seems to have fixed that and is very enjoyable.

---Gary
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Old 2nd July 2012, 02:11 PM   #363
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Quote:
Originally Posted by GaryB View Post
Joe,
Any comments on the benefits of the SLCF compared to the simple cascoded source follower circuit that I use?
---Gary
Hi Gary

I don't want to draw the wrong conclusion, but if you are using the fet follower with the constant current source and not the bootstrapped device I am showing, then there is quite a difference. Essentially the SLFF (and SLCF) runs in both constant current and constant voltage modes. It is common to see the CCS - but its also important that the actual follower element sees a constant voltage. What in reality is happening is that input (Grid or Gate), the output (Cathode or Source) and static element (Anode or Drain) are all seeing the same AC signal. Normally followers are one hundred feedback devices, you are using a trick to alters that state.

This is a quote from another forum:

"Good to hear from you John. It is really fun to watch the SLCF in action. If a 10.00 Vrms signal is applied to the grid, there will be a 10.00 Vrms signal coming out of the cathode, and the plate will also be following along with the 10.00 Vrms signal. They all move together as one. There is no gain or loss of signal, from in to out.... Paul Speltz"

Cheers, Joe
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Old 12th September 2012, 04:06 PM   #364
chi0001 is offline chi0001  Hong Kong
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Default buffalo 3 dac

anyone can help me?
i have a output transformer, and i want to connect it to buffalo 3 dac o/p, here is the pic, which no.1,2,3 is correct?
Click the image to open in full size.
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Old 18th September 2012, 02:36 AM   #365
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Originally Posted by reactivepower View Post
I have an Emotiva amp that it is used with that has high gain so I needed to step down the signal. I found the -12dB that these transformers attenuate helpful. At full volume the signal is quite loud but listenable. This works out to about 50W into my speakers.

I am using a volumite for the volume control. Prior to this setup I have used both Legato 3.1 and IVY. I thought these were very good, particularly Legato SE, but there was a little grain at lower volumes, where I listen quite often. The transformer eliminates this and has a nice smooth sound at low volumes. I think this might be attributed to the high common mode noise rejection of the transformers, plus with the attenuation the DAC is outputting more signal.

I am quite happy with this combo. Although I still plan to do some more experimenting...
Quote:
Originally Posted by Russ White View Post
Lowering the gain of the previous two output stages will likely yield similar (or maybe better) results.
I haven't yet reported back, but I did try Russ' suggestion. I modified the Legato balanced stage with ZFoil resistors, and the opamp stage with Dale PTF film resistors. The new output level of Legato is 600 mV FS. Sounds great! Unfortunately, now that it's burnt in I can't do a very good comparison from memory, and an AB comparison is difficult. Regardless though, it sounds so good I don't think I will switch back again anytime soon.

I know this is a little off topic, but I thought I should let you know I switched back from transformers and am quite happy.
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Old 18th September 2012, 02:39 AM   #366
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Quote:
Originally Posted by reactivepower View Post
I haven't yet reported back, but I did try Russ' suggestion. I modified the Legato balanced stage with ZFoil resistors, and the opamp stage with Dale PTF film resistors. The new output level of Legato is 600 mV FS. Sounds great! Unfortunately, now that it's burnt in I can't do a very good comparison from memory, and an AB comparison is difficult. Regardless though, it sounds so good I don't think I will switch back again anytime soon.

I know this is a little off topic, but I thought I should let you know I switched back from transformers and am quite happy.
That's all that matter's. I bet it does sound great.
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Old 18th September 2012, 03:11 AM   #367
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Quote:
Originally Posted by chi0001 View Post
anyone can help me?
i have a output transformer, and i want to connect it to buffalo 3 dac o/p, here is the pic, which no.1,2,3 is correct?
Click the image to open in full size.
How does "1" work. Or am I missing anything?

"3" will give you the full output of the DAC, assuming transformer is 1:1 ?

"2" will give somewhat reduced output, but give a fuller and more pleasing sound. I would ground the resistors, and even experiment with values.

Up to you, see what you like best.

Cheers, Joe R.
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Old 19th September 2012, 03:46 PM   #368
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Default buffalo dac 3

hi, i have one question,
I have the buffalo dac 3 and would like to connect it direcly in my preamplifier,
My preamplifier is audio tekne push pull circuit with transformer 30k-30k
in cd imput.

i know that the buffalo dac is 781 ohm
I ask you the matching impedence is realizzated ?
the dc osfet it can a problem ?

thanks for the Help....
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Old 25th October 2012, 06:24 AM   #369
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Joe see this:

DAC-END R (ES9018)
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Old 25th October 2012, 06:59 AM   #370
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Quote:
Originally Posted by audiodesign View Post
Joe see this:

DAC-END R (ES9018)
Oh, that was you? OK, no worries.

Cheers, Joe R.
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Last edited by Joe Rasmussen; 25th October 2012 at 07:03 AM.
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