[Doug Eisemann]

Hello all,  and my apologies as I ramble a bit to explain my situation.
I very recently became interested in the Red Wine Audio products as the idea of battery power really appeals to me, and I am in need of a simple but very good preamp.

I build custom tube gear for other people,  and have many vintage amps myself, (most in states of disrepair)  but I do most listening on a variety of vintage and modern speakers, with an AudioSector Patek SE amplifier that I dearly love.  It is one of the few solid state pieces which I have truly enjoyed and love it's simplicity,  ample power for less efficient speakers, and musical yet transparent sound.   It may seem strange,  but the last thing I want to do is build an amp for myself or goof around for hours with my own gear after working on someone else's all day!

That said,  I have found it sounds best with an excellent preamp in front of it, rather than simple passive attenuation as I am currently using with a tube phonostage of my own construction as my main source.

Hence my interest in the Isabella preamp,  perhaps along with the DAC option, as I am not totally against digital if done right.   

Seeing as a few other people on this board have experience with the Patek amps,  just wondering if this might be a feasible combination,  given the fact that I enjoy an engaging and musical sound without going too much into the warm and lush territory!   

Financial constraints prohibit a purchase in the immediate future,  but so far I have a good feeling about Red Wine Audio and it's products,   and would love some feedback.     I  suppose the possibility even exists for running the Patek on battery power at some point.

I appreciate any comments or observations.
Many thanks and regards
Doug Eisemann

[Vinnie R.]

Hi Doug,

Welcome to audiocircle and the RWA forum!

That said,  I have found it sounds best with an excellent preamp in front of it, rather than simple passive attenuation as I am currently using with a tube phonostage of my own construction as my main source.

IMO, a good tube preamp can really enhance the sound of a solid state amp (or "chip amp" in the case of our Patek).

Seeing as a few other people on this board have experience with the Patek amps,  just wondering if this might be a feasible combination,  given the fact that I enjoy an engaging and musical sound without going too much into the warm and lush territory!   

I'm very confident that the Isabella will add more richness, tone, and dimensionality to your amp.  Isabella is not overly warm or lush - and I think you'll even find that it will add more weight and dynamics to the table (and a more toe-tappin' experience) - especially when compared to a passive preamp.  A good passive preamp should give the best transparency, but won't bring the goodness mentioned above 

Financial constraints prohibit a purchase in the immediate future,  but so far I have a good feeling about Red Wine Audio and it's products,   and would love some feedback.     I  suppose the possibility even exists for running the Patek on battery power at some point.

YES - With a Black Lightning Series 12 running +/- 24Vdc, things could get VERY interesting 

I must say that I'm not sure if I have Isabella customers running Pateks (but a lot running Sig 30.2 and 70.2s  ), but hopefully we'll get someone who does and some discussion on this...

All the best,

Vinnie

[Doug Eisemann]

Mr. Rossi,

Many thanks for the comments and warm welcome!   I wasn't sure if anyone else around here had the Patek, but I thought I remember seeing someone mention it in an old post while doing a search.   Would really love to hear the 30.2 or 70.2's  at some time as well.

I do think the Isabella would be right up my alley so to speak.  The battery supply really interests me,  and it's received so many glowing comments,  it's certainly on my short list of gear to try. 
The Black Lightning really would be interesting,    as it would be really nice to get rid of rectifiers in the system all together.   

One other question regarding phono stages.    Are you still thinking about releasing a phono preamp at some point?   I see that you had been working on a design a while ago.   In my experience a seemingly simple phono stage can be the hardest thing to get right!

Thanks again for the comments.  I really appreciate it when the owner of a company is so directly involved with their customers (and potential ones).

Best Regards!
Doug Eisemann

[Vinnie R.]

Hi Doug,
 

In my experience a seemingly simple phono stage can be the hardest thing to get right!

EXACTLY - and yes, this is still in the works.  But I cannot say when it will be ready, but my aim is for it to be out in 2010. 

I do think the Isabella would be right up my alley so to speak.  The battery supply really interests me,  and it's received so many glowing comments,  it's certainly on my short list of gear to try.
The Black Lightning really would be interesting,    as it would be really nice to get rid of rectifiers in the system all together.   

A high-current SLA powered Patek ought to be pretty amazing paired with the Isabella.  Feel free to contact me in the future if I can be of service...

Thanks again for the comments.  I really appreciate it when the owner of a company is so directly involved with their customers (and potential ones).

This is the only way I do it - and have been since Day 1. 

Thank YOU for your post, and your interest.

Best regards,

Vinnie

[Stu Pitt]

Vinnie,

I've personally found through a few demos of gear that the pre-amp is definitely one of the most important components in the chain, if not the most important (assuming the amp is properly driving the speakers and not near clipping, and the speakers are properly placed).  I also think its the most overlooked piece.

In your desigining and testing, do you concur?

[Vinnie R.]

Hi Stu,

Yes - I agree that the pre-amp is very important (and yes, often overlooked), but it's hard for me to say it is the "most important" because everything else really matters.  Speakers, amplifier, source, room acoustics and speaker placement, and even cables all come into play. 

Like making a good stew (no pun intended, Stu  ), all the ingredients need to be there and working together to give that very special (and hopefully addictive) taste. 

Interesting discussion! 

Vinnie

[Earman]

I have a Red Wine Isabella, and I recently purchased a LM3875 Premium Amplifier kit http://www.audiosector.com/lm3875.shtml from AudioSector, maker of the Patek amp. The premium version of this DIY GainClone amplifier kit uses the exact same electronic components and circuit boards as AudioSector's Peter Daniel uses in constructing the Patek amp, although the DIY builder needs to provide his own power supply, connectors, housing, etc.. It will be a couple of weeks before I have a chance to assemble the amplifier kit, but after I do, I should be able to provide some meaningful comments about its sound in combination with the Isabella preamp.

[Stu Pitt]

Thanks for your thoughts Vinnie.  Maybe my saying the pre-amp is the most important part is a bit strong.  I think they're probably so over looked because they're not as 'sexy' as amps, speakers or sources.  They do a lot more than just switch sources and adjust volume.   

[Doug Eisemann]

Thanks to everyone for the very helpful discussion regarding preamps in general.    I agree,  the preamp seems to be quite overlooked in a lot of systems.     I was under the assumption for the longest time that a "preamp"  in the sense of active electronics was just another thing to mess up the purity of the audio signal.

However,  I am starting to think that a good preamp is especially important in the home system where impedance mismatches between gear can really wreck system synergy,  not to mention cause simple gain structure problems.   

In response to Earman,   since you are building your LM3875 amp yourself,   and need to construct the power supply,   this would be a great chance to experiment with battery supply!   
Hope the amp build turns out well and I look forward to hearing what you think of the results!

Thanks and Regards!
Doug E.

[adamaley]

Srajan of 6moons.com in his Isabella review had an Audiosector Patek SE listed as one of the associated components used in the review. Perhaps you could shoot him an email concerning the combo. It appears he does a good job responding to emails.

[Vinnie R.]

However,  I am starting to think that a good preamp is especially important in the home system where impedance mismatches between gear can really wreck system synergy,  not to mention cause simple gain structure problems.   

Hi Doug,

This is very true!

Hi Earman,

Thanks for sharing your experiences when you have it all built!

Hi adamaley,

Good idea - I'm not sure if he tried this combo, but it is worth a shot!

Vinnie

[Earman]

In response to Earman,   since you are building your LM3875 amp yourself,   and need to construct the power supply,   this would be a great chance to experiment with battery supply!

For this project, I'm pilfering a nice toroidal transformer and some other parts (switches, connectors, etc.) from an old amp. The LM3875 kit includes the rectifier board and its parts. A battery powered set up would eliminate the rectifier board and feed DC directly to the amp boards.

I think the LM3875 needs a minimum of 20 volts into each channel, so I suppose I could just use a pair of 12 volt batteries in series. However, each amp board in the LM3875 kit takes two separate sets of voltage inputs (V+/G+, V-/G-, i.e. four wires for each board, or three with a common ground). I'm not really an electronics guy, so it's not obvious to me how I would power that from just one pair of 12V batteries. Of course, it should be a piece of cake for Vinnie.

[Vinnie R.]

Hi Earman,

You would need four 12V batteries - two for +24V, and two for -24V 

Keep us posted!

Vinnie

[Alwayswantmore]

You guys mention the importance of the preamp, as a very satisfied Isabella owner I don't disagree. But one of the big selling points for me with Isabella is the sound of the optional DAC, and for another $500 you can add a pretty top-end headphone stage. IMO, an unbeatable value in purest hi-fi. Kent

[Doug Eisemann]

Sorry for my late reply,  it's been a busy week and I am getting a nasty cold, so it's been hard to focus on things!
Anyway,  some great ideas have been brought up,  many thanks!
I do think the Isabella represents a great value,  especially with the DAC option etc.   Can't wait to get a listen to it sooner rather than later.

Thanks again,
Regards
Doug E.

[Earman]

Here's an update on my LM3875 GainClone amp kit build for use with my Isabella preamp. In a nutshell, it's done, and it sounds great with the Isabella. Most notably for an AC powered unit, it is incredibly quiet. I have to put my ears within an inch of the speaker drivers to hear any noise at all. Given how quiet the amp is, any upstream noise would be easily heard, so the Isabella seems like an ideal preamp to combine with this amp. Even with the Isabella set to zero gain, and the LM3875 configured for just 26 dB of gain, the combination has plenty of volume and plenty of power for my 86 dB speakers in my room.

I used the "premium" version of the LM3875 amp kit from AudioSector, along with a Talema (German-made) toroidal transformer. I built it up in a minimalist configuration, with no smoothing caps on the rectifier board, no input resistors on the amp boards, and no zobel networks. The Caddock feedback resistor is mounted directly to the LM3875 pins, for shortest possible feedback loop. I believe this is how Peter Daniel of AudioSector assembles his own Patek units, except with the power supply in a separate housing.

I put my whole amp into a 3/8-inch thick aluminum housing that I salvaged from an older 25wpc Class-A solid state amp that had consumed 80 watts at idle. The GainClone is only pulling 4 watts at idle. With the overkill heatsinks that are mounted on the housing, the amp can run for hours on end and barely get above stone cold temperature. I think keeping the LM3875 chips so cool is one key to its low noise.

Another key factor in minimizing noise was using the star power grounding technique (http://www.diyaudio.com/forums/audio-sector/123003-commercial-gainclone-kit-building-instructions-8.html#post1518369) recommended by Peter Daniel. And the third major factor was keeping all internal wiring as short as possible. (For example, the wires connecting the speaker binding posts to the amp boards are less than 3 inches long.)

I had never built my own amp before, so it's quite gratifying to hear something I assembled with my own hands sound so good. Would it have sounded even better if I had used battery power? I can't say without trying it. I'm quite satisfied with the amp as is. Maybe someday I'll get the urge to take it off the grid, although the prospect of having to use four SLA batteries isn't very appealing.

In any case, I think that Doug (the original poster in this thread) can't go wrong by pairing his Patek amp with an Isabella.

[Doug Eisemann]

Earman,
Many thanks for sharing your experience.  This is exactly the kind of feedback I was looking for.  I am now more confident that this would be a good choice,  and is still appealing to me over all the other options that are on the market.
Unfortunately,  some more expensive auto repairs have pushed back any hopes of an audio purchase right away, but it will eventually happen.

A million thanks again,
Doug Eisemann