Who uses SS Amps and Tube preamps?

[cjgeraci]

Mark said:

"Ha ha - no, I was just trying to be funny. BTW, see the last post under 'PUNCH ANYONE' to see just how severe the QSC load is on a typical tube preamp."

Gang:

Just to clarify one thing related to the use of Juicymusic tube pres to drive QSC PLX amps. Yes, as Mark noted, the QSCs provide a severe load on a typical tube preamp, and the amp's input impedance puts a strain on a tube pre. That being said, however, in my experience, you can still derive some very nice low to medium to high volume performance by using the Blueberry mode/QSC combination so long as you are not preoccupied with bass "punch." Yes, there is some nice bass present in that combination, but not the sort of "punch" present with the superloz mode or with other some preamps.

Just wanted to point that out because I enjoy running QSCs with my Peach, both in the Superloz and the Blueberry mode. Then again, in Blueberry mode, I can run four horn-loaded speakers with a nice sub, and sometimes, I just do not miss the "punch" all that much in that mode.

Depends on your preferences and what you are looking for in your sound.......

Carl.

[stormin]

Just wanted to point that out because I enjoy running QSCs with my Peach, both in the Superloz and the Blueberry mode. Then again, in Blueberry mode, I can run four horn-loaded speakers with a nice sub, and sometimes, I just do not miss the "punch" all that much in that mode.

Carl.

Carl,

Does the sound change quite a bit in each mode? Could you briefly describe the kind of sound you are getting with each mode? Do you always run a sub?

Thanks,

Randy

[cjgeraci]

Ok, I'll try . . . . .

The Peach is unique in that it has two different tube line stages: 1) the standard "Blueberry" stage, which is found in the JM Merlin, Blueberry (standard & extreme), and is the regular stage in the Peach.; and 2) the superloz stage, which is unique to the Peach. For some sake of reference, I have run my Peach with a variety of solid state and tube amps - and with regular and modded Belles, regular and modded Altec Valencias, Cornwalls, RF-7s, and RF-3s.

First, as has been outlined by Mark, there is the difference in output. If you talk in terms of a "clock" for your volume dial, sometimes you have to go to 3 p.m. in the Blueberry mode - to get the equivalent volume at 10 a.m. with the Superloz mode. So, at a minimum - per its design, the superloz drives harder to drive amps (or multiple amps).

The superloz mode (as compared to the BB mode) sounds to me like more prominent bass, more "punch" (every amp I've tried with it) and tighter bass. On the top end, there is a bit "brighter" sound - and it also sounds more extended on the top end. Some who have listened to both stages at my house - also think the superloz is actually sounding more detailed. I think that it probably an audible illusion since the top end is a bit more extended (and a bit more forward). Also, the BB stage is less noise overall so depending upon how clean (or noisy the recording already is), the BB prevents some of the $%%&^^% from getting through.

Some do not care for the superloz mode and think it sounds artificially enhanced up top. I preliminarly thought that until I put some pretty nice NOS tubes in that stage. Now, I run Siemens CCas in the superloz mode (the real thing - some of the grail tubes) and a nice Amperex Holland white lettering in the bb stage - and I actually prefer the sound of the superloz mode most of the time (except with some ultra compressed CDs - then even my tubed CD can't save them - on to BB stage). For vinyl, I like both modes.

I also think that Eminence and/or Beyma tweeters sound better than K-77s with the superloz mode (either alnico or square) when using either the stock tubes or some lesser quality NOS tubes and for a long time, I preferred the Blueberry stage for K-77s. Once I found the NOS tubes that suited my ears best for the superloz mode, however, K-77s then sounded very good also in that mode - even with its "artificial extension." My favorite NOS tubes for superloz mode are the above-mentioned Siemens and regular gold-pin Telefunkens.

Just ask those who attended the class reunion that Dave and I DJ'd yesterday with Vertical Cornwalls (w/ stock drivers and horns), a Peach and a QSC PLX, all in superloz mode.

Carl.

P.S. I usually run a sub, but it is not really needed when in superloz mode, but I usually use it in BB mode. That being said, some of the best sound I have heard in my system has involved, superloz mode, two Belles up front, two Altecs in rear - and my SVS sub - all running at the same time. Of course, room treatments and bass traps help a lot to cut down on reflections and tighten up the bass (and keep the bass from accumulating in certain spots in the room).

[stormin]

Carl,

Thanks for the excellent explanation of both modes. It appears Mark really made a gem with the peach. Well at least for us folks spinning cd's instead of vinyl.

Do you use anything special in the way of IC's and cables?

Sounds like an excellent set up you have there which i am sure has alot of time and thought put into it.

Thanks for sharing,

Randy

[sheltie dave]

I have tried a variety of tube/SS combos, and am currently running a HT Merlin/Teac combo upstairs, and have moved Brystons and Monarchy Audios through the Blueberry downstairs, along with Crown and JBL amps.

The Khorns downstairs don't have great corners, so I decided to pick up an RSW-15 to augment the musical bass, and to provide some slam on the rare occasion I have the house solo.

The Teac, at 30-35 wpc, does NOT have the back to do much slam. It can provide a fair amount of extension and some reasonable dig, but at $100 no one should expect a world class, or above average performance below 100 Hz. I run the system cheap because our three year old has learned how to go on/off, and will soon learn the volume trick.

The Blueberry can lift some heavy bass with the Bryston 3B, mainly because you need some headroom, and some stout damping factor, to really maintain control over the woof excursion. Titantic bass that grabs your digestive tract and squeezes your pyloric valve really requires a solid subwoofer if you want to liquify your foundation.

With the Khorns and Blueberry/VRDs AND the RSW-15, I can clear the basement walls with less than 30 watts. Our sheltie has to be outside, as he doesn't like the floor vibrations too much.

Carl's Peach(in superlow Z), QSC amp, and Cornwalls had the music cooking at about 30 wpc yesterday. We had close to 200 lady alums at the reunion, and they loved the sound. It was strange, as most people would be comfortable standing directly in front of the speakers without feeling they were too loud, and yet we could be a 1/4 mile away from the open air pavilion and think they were rocking the house. Zero distortion, no standing waves anywhere, and a glorious open sound with a commercial solid state amp. Hats off to an EBay $300 special!

[Deang]

Mark, is it possible to give some kind of acceptable or useable range of impedance for the Blueberry mode of operation? Also, if one drifts out of the range, what is actually happening to the signal?

[Deang]

I found the answer to my first question on the first page -- but I'm still curious about the second thing I asked about.

[Dirk Diggler]

My amp has an input impedence of 33K ohms. How would that mate with a Merlin?

[Marvel]

I knew that the SS amp I was using probably had a low input impedance. I finally dug out the manual for it. Yup, way too low at 7k. Much lower than I though it was. As if the LaScalas weren't a little shy in the bass already. Not sure what happens when it is turned on, but the input resistance is about 9k when powered off, and doesn't change with a change in the input volume pots.

I'll need to work in this. How about a simple tube buffer design, Mark?

Bruce

[tigerwoodKhorns]

Dirk,

I sent you an email.

Chris