XMAS Present

[blackraven]

I will be getting the relatively new Grant Fidelity DAC-11 DAC/Preamp for the holidays. I am looking forward to using it in my second system with my Class D audio amp and MMG speakers. It will interesting to see how it compares to the Maverick Audio TubeMagic D1 DAC/Pre that I bought for my son. The reviews on the DAC-11 have been good.

Grant Fidelity TubeDAC-11 D/A Converter

[Enochrome]

Please post a review!!! Can't wait. I have been torn between this one or the DacMagic

[blackraven]

Please post a review!!! Can't wait. I have been torn between this one or the DacMagic

I won't have it till Christmas. I will post an initial review then. It is supposed to be a big step up from the DAC-09 which my Maverick D1 DAC/Pre is a copy of and the Maverick was well worth the money.

[blackraven]

Here's a good review on the DAC-11

tubedac11

[E-Stat]

I will be getting the relatively new Grant Fidelity DAC-11 DAC/Preamp for the holidays.

Sounds like a great deal for the money. I think, however, their calling it a "tube DAC" is disingenuous since the lone 6N11 serves only as a buffer following the ADA4075-2 op amps used for gain.

I'd like to see an updated version of the Manley Delta Sigma DAC used in the vintage system where the two 12AU7s are the gain stage. Since it has separate left and right analog gain controls, you do not lose the ability to set balance.

[Feanor]

Sounds like a great deal for the money. I think, however, their calling it a "tube DAC" is disingenuous since the lone 6N11 serves only as a buffer following the ADA4075-2 op amps used for gain.
...

I've heard this is a pretty common tube application in case of "tube DACs" and, of course, tube buffers in general. I believe it is used in the Music Hall dac25.3 and the Monarchy NM34 as other examples.

In these cases the tube is definitely adding something to the sound, and I have to ask whether you can add anything without it being distortion.

There might be an exception where the upstream source has high output impedance. As I've heard, the tube works in a "cathode follower" configuration to present the downstream device with a lower impedance.

[E-Stat]

In these cases the tube is definitely adding something to the sound, and I have to ask whether you can add anything without it being distortion.

Which is the case for any active device - and why I use preamps for vinyl duty only. I'd much rather have a good triode design than one using high feedback op amps.

As I've heard, the tube works in a "cathode follower" configuration to present the downstream device with a lower impedance.

The Manley uses that approach along with being the gain source.

[Enochrome]

Triode for vinyl with a passive preamp might be the direction I am headed.

I was just about to pull the trigger on the DAC 11 on Audiogon. Someone had one for sale for $235, which was a great deal, but I had just purchased a new integrated the day before.

I did not know that the DAC-11 can be used as a passive preamp which was the deciding factor over the DacMagic, as well as the accolades from this forum. There is no way for me to demo, since I live in Los Angeles, so when the funds are in, I'll take the chance.

[Feanor]

Which is the case for any active device - and why I use preamps for vinyl duty only. I'd much rather have a good triode design than one using high feedback op amps.
....

I have followed your example and am now using a passive preamp; (mine utilizes a potentiometer).

My previous Sonic Frontiers preamp was all-tube using a cathode follower.

[E-Stat]

I have followed your example and am now using a passive preamp

How is that working out? When gain and impedance are matched, I find there's nothing else like the sound of...nothing!

[Enochrome]

Could someone explain the gain and impedance matching? I am not sure how to check for this? My new integrated has a passive preamp and I would like to make sure how to do this matching correctly for future changes in my system.

[E-Stat]

Could someone explain the gain and impedance matching? I am not sure how to check for this? My new integrated has a passive preamp and I would like to make sure how to do this matching correctly for future changes in my system.

Start with the amplifier. It has a sensitivity rating stated in volts - how many are required to achieve full output - and input impedance. The source needs be able to generate enough voltage (and a bit more) and with a much lower output impedance than the input impedance of the amp. Depending upon who you ask, the answer ranges from the source having one-tenth to one-hundredth that of the amplifier.

Most amps require about two volts for full output. Some like my VTLs - a bit less. Can the CDP/DAC deliver that output level? Is the output impedance of the source sufficiently low as compared to the input impedance of the amp? If not, the sound can be thin and rolled off at the top.

Both of the systems where I bypass a preamp for the digital source meet the impedance requirement. In the garage, however, the DAC cannot fully drive the amp. Which ends up not a problem at all given the levels I can achieve.

Is that plain as mud?

[Feanor]

How is that working out? When gain and impedance are matched, I find there's nothing else like the sound of...nothing!

It's working well for me. I notice no loss of dynamics nor roll-off with my power amp which is spec'd as 47 kohms input impedance. I'm driving my subwoofer in parallel too. The sound is excellent to my ear, being very resolved and grain free; this is especially obvious with the 24/88.2 and 24/96 downloads that I've have.

[Enochrome]

E-Stat

You explained so well that this flat head understood it. Most gracious thanks coming your way.
I bought a Acurus DIA 100 and am thinking of the Grant DAC-11 both use passive preamps that is why I ask.

[E-Stat]

You explained so well that this flat head understood it.

Cool. Preamps have evolved from being a necessary partner in raising the gain of phono cartridges 60-70 db so that an amplifier could do its job to now just being a buffer and control center. I chose the Audio Research SP-9MKIII because it provides 67 db of gain for my mid output MC cartridge with only two hybrid FET/triode stages and is dead quiet. By contrast, a current REF5 line stage generates only 6 db of single ended gain.