K&K Audio / Lundahl Transformers

Welcome! Need support, you got it. Or share youe ideas and experiences.

Return to K&K Audio / Lundahl Transformers

K&K Audio / Lundahl Transformers

Re: New DAC kit

24.136.237.79

[ Follow Ups ] [ Post Followup ] [ Thread: Display All Email ] [ K&K Audio / Lundahl Transformers ]

In Reply to: Re: New DAC kit posted by papagenohyun on May 26, 2004 at 05:04:24:

Hello Kim,
First, I must start by saying that Kevin is too reserved in his assessment of the sound. This DAC is absolutely incredible sonically. It is the best music reproduction that I have ever heard - period. Better than Kevin's superb analog vinyl setup, which prior to this is the best I have heard. It is not just Kevin and me saying this; we have people in line to buy all of the prototype boards. Everyone that hears it wants one.
Now, on to your questions. The RAKK DAC uses the BB PCM1794, which is the latest flagship DAC chip. It does have digital oversampling and digital filters. It seems that they have been doing their homework and are learning to do it right.
Right now, the plan is to supply components for the DIY to put together their own DAC system. If things go well and the components sell as we expect them to we will consider releasing a complete kit.
The components that we will initially offer is the RAKK DAC, an optional Tent clock board, a special version of the Minimal Reactance power supply, and two output boards. The RAKK DAC and the Tent clock board will be come assembled and the others will be kits.
The transformer output board is very simple and totally passive, having only a pair of Lundahl LL1674 transformers and load resistors. The tube output board is a bridged class-A SET parafeed design similar to the Raleigh Audio Line Stage tailored to be a DAC output stage. It also uses the LL1674 as output transformers. Both output stages are capable of 2VRMS at full signal. The major difference is in the output impedance and drive capability. The transformer output has an output impedance of almost 3K Ohms. In some systems this is okay, however if a system wants to see a low impedance, the result is that the sound is a little "tired." The tube output stage has a 250 Ohm output impedance and provides the drive that some systems like. In all systems this will provide a lively, dynamic presentation with plenty of sparkle.
The power supply board is a version of the Minimal Reactance power supply especially designed for the RAKK DAC.
Dave

Follow Ups:

Re: New DAC kit - papagenohyun 17:15:02 05/26/04 (1)
thank you for kind explanation.
i have some more questions.
1) you wrote as below
The components that we will initially offer is the RAKK DAC, an optional Tent clock board, a special version of the Minimal Reactance power supply, and two output boards. The RAKK DAC and the Tent clock board will be come assembled and the others will be kits
then, what will i need more to complete dac? only case work and gathering some needed parts and transformer?
2) what is more easier to build between the two?
and my preamp is supratek syrah which has 6sn7 parafeed output transformer coupled linestage.
can you guess if the passive output stage is going well with this preamp?
Mr.Kevin told that passive is ultimate, so i guess he prefers this design in proper condition.
so if possible i would like to go for passive version.
and is it really hard to assemble?
3) just give me some hints about price range. i have to check my bank accout first. ^L^
and when do you start to take orders?
4) in fact, i am very surprised that you prefer dac sound to kevin's lp sound. frankly speaking i cannot believe that comments.
it it really is true, you can count on my ongoing order!
but i think you all did very good jobs.
best.
kim
- Re: New DAC kit - Dave Davenport 22:05:19 05/26/04 (0)
  Hi Kim,
  You asked: then, what will i need more to complete dac? only case work and gathering some needed parts and transformer?
  Yes, that is correct. The power supply is designed specifically to use the Lundahl LL1683 power transformer, however you may substitute an equivalent if you wish.
  You asked: what is more easier to build between the two?
  Definitely the passive is easier, it has only two transformers and two resistors. Because of the fewer parts it is also cheaper. The tube output board is a sophisticated class-A triode bridged parafeed design.
  You commented: Mr. Kevin told that passive is ultimate, so i guess he prefers this design in proper condition.
  I believe that you misinterpreted his position. Kevin said "In my system the tube output stage had more "sparkle" in the treble, but was pretty comparable across the rest of the audio spectrum." What Kevin was referring to with his use of the term "ultimate" was the simplicity of the design. The tube is a much more complex design than the passive. However in his system the tube output board sounded better. Of course I can not know which would sound better in your system, however my guess is that the tube output should sound better in most systems. I am sorry that I cannot be more specific, however the RAKK DAC is new and we have not had the benefit of hearing it in a wide variety of different systems.
  You asked: just give me some hints about price range. i have to check my bank account first. ^L^
  and when do you start to take orders?
  We are in the process of pricing everything and will have the prices up in a few days. There are a few questions that we have on the prototypes and the final version is not complete for pricing yet. However, I am sure that Kevin will be glad to put you on the queue to get one if you contact him.
  You commented: in fact, i am very surprised that you prefer dac sound to kevin's lp sound. frankly speaking i cannot believe that comments.
  Yes, I don't blame you for not believing me. I would not have believed it if I had not heard it with my own ears. I expected that the result would be good but I was not prepared for the incredible sonics that I heard. It blew me away.
  Dave

This post is made possible by the generous support of people like you and our sponsors:

The Cable Cooker

You can not post to an archived thread.