Eastern Electric Minimax BBA preamp (not typical EE preamp) with RWA products

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Flashman

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I have just purchased some used Odyssey Lorelei speakers but am having a volume issue with my RWA 30.2 due to the lower output of my Olive Musica (1Vrms vs. 2Vrms of a typical CDP) and the lower sensitivity of the Lorelei speakers (89db at 6-ohm) compared to my previous super efficient Klipsch Forte speakers (98db at 8-ohm).

After reading the RWA board, I was thinking about adding an Eastern Electric preamp (also to add that elusive holographic sound that the RWA products come so close to matching) when I discovered an interesting product: the Eastern Electric Minimax BBA Preamplifier that retails for $850.  This is not the EE preamp that some of the folks are using with their RWA products but a product that raises the gain (in an adjustable manner) and also uses tubes, which can be rolled.

http://www.dagogo.com/EasternElectricBBA.html

Has anyone had any experience with this product and the RWA products?

Just to makes things interesting, please read the following excerpt from Bill O'Connell, the importer of the Eastern Electric gear, to me (I also asked him about the heat from the BBA and the preamp, since I put my components in a cabinet):

"The MiniMax preamp runs much cooler then the BBA, the BBA with its surrounding metal gets very warm but this really shouldn't be much of a concern. The BBA would be the component to probably use as it was made just for this situation.  I do think the MiniMax preamp though is so versatile in its tube rolling capabilities to truly dial in the tone that you would want with a swap of a tube or 2 that this might be the ticket also. But then again you could roll a couple different tubes in the BBA and probably this might do it for you.  The 30.2 integrated would probably benefit more from the BBA IMHO as a full preamp just isn't necessary in your situation.  Nice choice by the way, this is the current Full Lunar Eclipse Award winner from 6mooons is it not?  I met Vinnie once when I was visiting Louis of Omega speaker fame."

Thanks for any feedback!

Vinnie R.

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Hi FlashMan,

I cannot comment on the sound of the BBA with the Signature 30.2 because I have never heard this unit, however I am somewhat concerned about the output impedance spec of this unit:

Quote
Output Impedance: 800 ohms- 10K ohms

The input impedance of the Signature 30.2 with volume control is a constant 20k.  If the output impedance of the BBA increases beyond 2k (I assume by adjusting the gain knob on this unit), this *might* not be a good match.  :scratch:

There are a couple of solutions that I can think of:

1) If you do go for the BBA, you might want to consider sending me your Signature 30.2 to have me convert it to the power amp version (no volume control) as this has an input impedance of approx. 100k.  This should be fine for all settings of the BBA output impedance.

2) Go with the EE Minimax pre instead, as its output impedance is spec'd at:

Quote
Output Impedance: 700 Ohm

and this will be fine with your Signature 30.2 with volume control.... and having the volume control on the Sig 30.2 is, IMO, a good thing with this preamp as it has BIG gain of 20dB!  You can set the volume control of the 30.2 to a position that will allow you as much useable range out of the MiniMax's volume control. 

The MiniMax also gives you input select for multiple sources... you never know when you are going to add another one!  :green:

I hope this helps,

Vinnie

Flashman

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Quote
The input impedance of the Signature 30.2 with volume control is a constant 20k.  If the output impedance of the BBA increases beyond 2k (I assume by adjusting the gain knob on this unit), this *might* not be a good match. 

There are a couple of solutions that I can think of:

1) If you do go for the BBA, you might want to consider sending me your Signature 30.2 to have me convert it to the power amp version (no volume control) as this has an input impedance of approx. 100k.  This should be fine for all settings of the BBA output impedance.

2) Go with the EE Minimax pre instead, as its output impedance is spec'd at <Output Impedance: 700 Ohm> and this will be fine with your Signature 30.2 with volume control.... and having the volume control on the Sig 30.2 is, IMO, a good thing with this preamp as it has BIG gain of 20dB!  You can set the volume control of the 30.2 to a position that will allow you as much useable range out of the MiniMax's volume control. 

The MiniMax also gives you input select for multiple sources... you never know when you are going to add another one! 

I hope this helps,

Vinnie

Indeed, it does help, Vinnie!  Thanks for alerting me to a *potential* mismatch of my Sig 30.2 with the EE BBA.  I don't want to further modify my Sig 30.2 to overcome this possibility as I am very happy with the product.  And well said about the flexibility of the EE Minimax preamp, which is used by a number of RWA posters.  Well, the choice then is to go with the Eastern Electric Minimax preamp or to wait for the Isabella.  Or, I could double back to my Klipsch Forte speakers, which were, in hindsight, a pretty nice match with the Sig 30.2.  A tough quandary, no doubt.

Thanks Vinnie for your continued insight into our wishes to maximize your products with ancillary products.

Flashman

carusoracer

Both EE products and Red Wine are considered very good. I have not heard the Red Wine but know many that have
I have the EE Minimax and have auditioned the Buffer unit, the comments are spot on regarding gain and sound. It is a very flexible unit. I would go with the Minimax pre they also have one for a phono stage if that is an option for you. It does have as stated a huge amount of gain. Talk to Bill at Morningstar he is a very good source and gentleman.

Good luck!

flaneb

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Hi,
I am the proud owner of a sig 30 that I will be upgrading (attn Vinnie) after the holidays, but I also have 2 minimax preamps (modded in different
ways) and 2 BBA's...I have tried both and prefer the preamp. The BBA's best use for me has been with subs, which they transform to
another level. I have also used the sig 30 with and without a preamp, and in my system I strongly preferred the pre amp. The eastern electric
pre is a giant killer and you have the bonus of dealing with Bill OConnell who's the best there is and knows tubes intimately.
regards
frank

texendo

I just got my modded EE pre back today and am using it with my Sig 70s.  It was a nice preamp to begin with, but man, it's a heck of a lot better now.  The reduced gain makes a big difference for the better, but right off the bat I notice that the pre is MUCH quieter than before.  Nothing's even broke in yet, so I anticipate things to improve over the holidays while I let it burn in a bit : )

Vinnie R.

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It does have as stated a huge amount of gain.

Yes, 20dB is a lot of gain.  The Signature 30 already has 29.5dB of gain.  I'm thinking Flashman would benefit from 6dB of gain, but not much more than that.

Quote
It was a nice preamp to begin with, but man, it's a heck of a lot better now.  The reduced gain makes a big difference for the better, but right off the bat I notice that the pre is MUCH quieter than before.

Thanks for your feedback, Texendo.  Reducing the gain of that preamp reduced its SNR (and most likely also lowered its output impedance), so I'm sure it is much better match with your Sig 70s!

Thanks for your feedback as well, Frank!

Best regards,

Vinnie

carusoracer

I just got my modded EE pre back today and am using it with my Sig 70s.  It was a nice preamp to begin with, but man, it's a heck of a lot better now.  The reduced gain makes a big difference for the better, but right off the bat I notice that the pre is MUCH quieter than before.  Nothing's even broke in yet, so I anticipate things to improve over the holidays while I let it burn in a bit : )

Frank and Tex,
What is the mod that you are talking about from EE specifically. You can PM

Now back on topic, Thanks

texendo

It's offered by the importer Bill at Morningstar Audio.  He has one of his engineers significantly increase power supplies, cut the gain to about 9db, upgrade resistors and caps, and change the middle tube all for $300.  Had the unit back in my system in under two weeks using ground.  Absolute no brainer.  My rig sounds too good!!  Many others here use this same modded pre with their RedWine Sig amps; outstanding synergy.  I just wanna eat it up.



Vinnie R.

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Cool pic, Texendo!  :thumb:

dangerbird

Dredging up an old thread--is the minimax phase inverting?

Sigfreed

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I own a modded EEMinimax Pre. Not sure which mod it is exactly since i bought it new with the completed mod around 2 years ago or so. Yes it is phase inverting.  I have my speaker terminal connections reversed and it sounds great.  It is the only active tubed preamp i have ever owned and am very pleased but am always open to suggestions if anyone has any in that price range? Was thinking of the Mapleshade 6sn7 based pre. Anybody have any direct comparisons of the EEM and the Mapleshade Pre?

Also, just recently had my Sig 30 upgraded to the 30.2 and everything that has been said about this mod is spot on. I am very pleased and will write some thoughts and observations when i reach 200 hours.

dangerbird

Thanks for the reply, mine has been modded as well(I think Mr. Tutay) did the mods,so far I've been very happy with it.

carusoracer

Phase inverting? That is the first I have heard of this. I have had my MinMax pre for a few years now.
Where did you see this or can your refer me to a link :scratch:

Sigfreed

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Ya know i actually have no idea where i stumbled upon that information but was on some thread somewhere. I was running it normally and it sounded ok but when i swapped polarities at the speaker terminals, as was suggested in that thread, it got way better and the soundstage opened up tremendously. I am sure i confirmed this with Bill from EE before settling on this. To be on the safe side, and for your own peace of mind, i would talk to him as well. There have been a bunch of mods floating around on this preamp and who knows if anything changed in the different mods?? I am pretty ignorant when it comes to the technicals but i definitely remember mine being a phase inverting preamp and that is how it stands today and sounding mighty fine with those terminals swapped.

OK i just did a quick google search on this and found something. Read the third to last post on this thread. Hope this helps! And i also hope it is ok for me to post this thread on here?????  :scratch: :duh:

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1068862640&openflup&12&4#12




tbabb

Have you tried something like the Anti-Cables Autofomer?  Seems like a simpler approach and a shorter signal path.

http://www.zeroimpedance.com/Zero-New.html


MttBsh

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I too must put in a good word for the EE Minimax preamp. I bought one primarily for gain as, even on my 95 dB speakers I had to crank the volume on my sig 30.2 almost to the max for movies, and that put a drain on the batteries, reducing the number of hours I could keep the amp on when I have friends over for the evening. I was pleased that the Minimax provided more than enough gain, plus an overall improvement in sound. But when I added the 3 NOS tubes that Bill O'Connell (importer of EE Products) recommended, I was stunned by the additional "weight", refinement and 3D soundstage it brought. It takes all of the strengths of the 30.2 to a completely new level. I was able to find a used Minimax (recent, upgraded version) and the NOS tubes all for well under a grand. I imagine the Isabella would beat it, but, based on my experience, the Minimax represents an excellent upgrade path for 30.2 owners on a budget. BTW, I recently bought a used Audiosector DAC for under $300 and that trounced my old Scott Nixon Tubedac and it too has great synergy with the 30.2. My stereo now sounds almost too good to be true.

Here are Bill O'Connel's Minimax tube recommendations - and I concur!:
http://db.audioasylum.com/cgi/m.mpl?forum=amp&n=135602&highlight=minimax+preamp

toobluvr


The EE Minimax preamp does indeed invert phase.

Straight from the horses mouth....see Bill O'Connell's first post in this thread:

http://www.audiokarma.org/forums/archive/index.php/t-156071.html


Vinnie R.

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The EE Minimax preamp does indeed invert phase.

Straight from the horses mouth....see Bill O'Connell's first post in this thread:

http://www.audiokarma.org/forums/archive/index.php/t-156071.html

Hi Guys,

I know there is a lot of discussion about "what components invert phase."  But here is a simple solution that I recommend trying:

Simply flip the polarity of the speaker cables to BOTH of your speakers and listen.  And then flip back - see if you can hear a difference.  If you can, use the configuration that sounds best.  If you can't hear a difference, then just forget about it and enjoy listening to your music...

They way I see it, there is no reason to be too concerned about which of your components invert phase - just connect everything and flip the polarity on both speaker cables and listen for yourself - and pick what sounds best.  There is nothing wrong with flipping the polarity of both speaker cables (either at your amp, or at your speakers) if you can hear an improvement in doing so.

Of course, keep in mind that some recordings were recorded with inverted phase and some without inverted phase - so I guess you can drive yourself crazy with this if you want to.  :green:

Just remember - when we talk about phase being inverted, we are talking about the "absolute polarity" (both channels have inverted phase).  Clearly if you only flip the polarity on one speaker only - it is going to sound terrible and very, very easy to hear this  :wink:

Just my 2 cents on this...

Vinnie