[tubes]

Hi Bill, did you have any trouble getting the transformer off the board, someone had mentioned it may be glued down. Thanks for the good pictures, I'm waiting for my DC-30 to arrive then I can move on to the caps, resistors etc..

 

[Bill Allen]

Rich-

The problem with the piggy back 1543 DAC chips is how do we cool the DAC chips located underneath. I am afraid we would run into the same overheating problems all the pioneers of this design suffered from. TeraDak solved this issue by laying the chips flat aganist a heat sink. Simple yet effective.

Maybe Teradac will make a 16 DAC chip version in the near future. One could simply remove DAC chips, match I/V resistors, and tweak the output voltage of the DC-30 for optimum gain and sound quality in their system. Very cool.


Phil-

No problem removing my power supply, I simply sucked and wicked the solder out, then wiggled it right out. No glue!

 

[PatOMalley]

Took 'em out, Bill. And I am ready for any comments about that wire burning in. It is the wire I was using to run from caps to RCAs on this same board so it is back home.

I only removed the caps. I don't want to fiddle with the switch yet. The more I look at that switch the more I think "NOISE".

After all these changes today I am starting to hear subtle weirdnesses. Meaning I can pick up the production stuff more. Like Nina Simone's voice being much far forward than the piano. They enhanced that voice. On stuff like Rudy van Gelder recorded music you get a nice halo or shimmer on piano or some airy thing. You also get this sense of the touch of the finger, sort of like the voicing of the note that is a personal bit of the music. This DAC is now reifying the previous reality of the music. Plato's shadows dancing on the wall are gaining focus.

I did get hung up on matching the load on the transformer but the last time I did that with my Cinemag fed by my Denon DL103 cart the effort was worthwhile. That 'project' was an analog to this one. [humor] So I think some things can be gathered from other things and applied. Trying it yourself removes all the "will this work" and "how does it sound if" pensive conjecture.

Words about those Jupiter caps are a major taunt. But then what about the Mundorf Silver/oil?

Phil, I had a problem with removing my transformer but I wasn't using enough heat. I went back and took care of it the way Bill did and it came off. I used a solder sucker and made a real soup of the solder. I would not bend or pry that transformer off as it will stress that board too much. But you already knew that.

 

[tubes]

Pat, I just noticed in your picture you removed the .01 caps and replaced with a jumper. Any gains?

 

[Bill Allen]

Pat-

A student of Plato I see. However making it real is more up the alley of Aristotle. When does recorded music actually become music? When we suspend belief and make it real in our head. Then music becomes what it has always been ... music to "our" ears.

Gee the more I reflect on your digital coax input project, the more the path illuminates. Loose everything. I would remove the RCA jack, cut off the end of your digital cable and stuff the cable inside the hole. Solder it directly to your new transformer which should be mounted right next to the 100 ohm resistor on the board. Done.

The proof is in the pudding!

 

[PatOMalley]

Phil,

The effect is subtle but when you sit and listen for a while you pick up things like how 'they' move a voice forward or did certain production things. It doesn't hit you in an unpleasant way.

One well recorded unproduced stuff you get a nice feel for what they are doing. Fingers on keyboard, valves on horns, voicing on notes.

The thing about these changes they all seem incremental ... if you were to have done all stuff at the same time it would probably wowed the hell out of you on first listen. And thereafter for that matter.

 

[PatOMalley]

You're going to kill me, Bill. You suggest these things and I then have to go do them. And I have no air conditioning in the workroom in the basement.

I would argue against Mr Burklee that if a tree falls in the forest it makes noise. That noise happens in our heads. So then what is music but a shared hallucination? A mass conspiratorial fuzzy consensus. What becomes of objectivity? Let's not get started on ABX tests!!!

Reality is a gentlemen's agreement always under renegotiation.

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif Pat- A student of Plato I see. However making it real is more up the alley of Aristotle. When does recorded music actually become music? When we suspend belief and make it real in our head. Then music becomes what it has always been ... music to "our" ears. Gee the more I reflect on your digital coax input project, the more the path illuminates. Loose everything. I would remove the RCA jack, cut off the end of your digital cable and stuff the cable inside the hole. Solder it directly to your new transformer which should be mounted right next to the 100 ohm resistor on the board. Done. The proof is in the pudding!

 

[Bill Allen]

@

 

[r8833]

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif Maybe Teradac will make a 16 DAC chip version in the near future.

Lets not push him ..I have too many dacs..3 valabs and a monarchy m33 modded by Stan Warren

 

[r8833]

Talked to teradak about piggy backing another 8 chips. He said its possible and need to change I/V to half the value..I'm gonna give it a try just need a new chassis and design a heatsink to cool the chips

 

[rhodes54]

I have not reading the board for a few days and a lot of useful information has been posted again.

@ pat & bill: I always had my questions about those 0,01uF filmcaps. Why use a filmcap on this spot? It makes no sense to me. I think a Vishay MKP1837 or Sanyo Oscon SP will do a much better job, if that cap is needed at all.
I will do some experimenting with it this weekend and see if changing caps will give a step forward.

 

[rhodes54]

Guys, this week my Paul Hynes power supply arrived. It took a long time but it was worth the waiting. I expected to hear changes like you reported about the DC30 module but I couldn't believe my ears when I turned on the DAC with the new power supply. This was not just an subtle upgrade but I huge one. Everything so tight, so quiet, so open, so much rest. It's unbelievable.

Until now the Valab was still in a battle with my heavily modded Benchmark because the Benchmark had a tighter bass than the Valab. But with the SR1-MR the Valab finally beats the Benchmark. And not just a bit... The Benchmark suddenly sounds cold, less transparent, less open, has grainy highs, etc.

I think it took the right decision to buy this SR1-MR from Paul Hynes and not the DC30.
The reason that I probably achieved better results is because this power supply is an ultra low noise design. Cleaner than clean.
Besides that I am using two seperate transformers and two seperate power supplies for my Valab now.

I will take some nice pictures for you soon.

My Dreamdac is finished, I'm satisfied. I love it.
A few things are left to do: The Lundahl transformer, the filmcaps in the digital signal line and that 100R resistor (in stead of 75R) are the only things I would like to add/modify. After that i'm done unless someone is coming up with a major "must do" change.
I will contact Michael from Teradak today to ask what's the reason they used that 100R resistor. Is it a well considered decision or just a "we don't have the correct value at hand so we take something close", like they did with more parts on the board.

I would like to thank everybody for their input. Especially Bill and Pat for their continuous input of great ideas, smart thinking and 'online brainstorming'

I'm done with the Valab (but not gone here).

Thanks again!

 

[maymnagonry]

Good Evening Everybody...!

This is sort of a continuation to a different post earlier (that I can't seem to find) discussing ESL & English Second Language Software. So I've done my part by trying to investigate as much as I can.

I found that out of all the Study Online English courses, the QGroupPlc ( Website: QGroupPlc.com ) offers the best services for the most affordable prices. The QGroup online study courses teach Grammar, Vocabulary, Spelling & more.

The English Study are great for for children, and I'm so happy that I finally found one!

Let me know what you think, and I would love to know about other sites offering these kinds of courses, I'm hooked. Besides that, I'm also looking to become an affiliate of English Vocabulary Software to make some extra cash

Thanks



English Grammar & Vocabulary Software Sites
ESL
ESL Courses
ESL Affiliate
English Vocabulary Software
English Learning
English Grammar Affiliate

 

[rhodes54]

Pat,

I had contact with Michael today and he gave us the answer on our questions regarding the transformer on the coaxial input by sending me one simple picture:



There's only one question not answered after looking at this picture, which Michael gave us: The 100R resistor is used to let the 26C32 work. This means that the coaxial input is not terminated in the current design. In order to let it work correctly with a transformer a 75R resistor needs to be added between pin 1 and 2 of the 26C32 (see picture). Or in other words: between pin 3 and 4 of the transformer.

Thanks again Michael @ Teradak for your help!

 

[rhodes54]

I removed the Russian 0.01uF filmcaps tonight and changed them for Vishay (ERO) MKP 1837's of the same value.
From what I heard so far (it's on for an hour or so) is that the sound is 'cleaner' than before. Less grainy highs and the bass seems less boomy and even a bit tighter. So far it seems another nice $1,- upgrade but I will listen to it for a few days first, then switch back to the russian filmcaps to see if I was really right.

If you have them at hand, just try them. I'm curious if other people experience the same.

b.t.w. I tried to bypass them completely like you did but that didn't work in my DAC: It didn't lock anymore and the sound was gone on both inputs.