Bi-amping MBL 101's - combining tube & ss

i'm thinking about a pair of mbl 101's. i currently use david berning quadrature z's at 200watts per channel. i love this amp and am wondering if i can biamp, using a bigger amp for the woofers, and run the berning's for the mid/tweeters. i don't want to yet endulnge in an external crossover. would like to somehow do this leveraging the internal crossover. thoughts?
34de1bbb e830 480f 89bf 7b1dc1b094a5davidhyman
I own a pair of mbl 101 i used for about 8 years but have abandoned them since tired by their metallic sound...the omnidirectional seduction is not enough to compensate this coloured sound no amp can cure...
The amp was an Airtight ATM2 with siltech flat wire,sounded not bad but no comparison with my Duntech Crown Prince speakers Which are neutral and extend down to 25 hz instead of 45...
Since my daughter has inherited these speakers ,i'll test soon a sds470 classdaudio amp of 250 w/8 ohms since this amp has a tube amp sound ,and is extremely neutral.Moreover, it is almost free of charge at 590$...
Good luck!
If your main amp's speaker connections inside your speaker's are equally split or "Y'ed" to each driver's crossover, it should be doable. Your "extra" pre-amp gain is key. Splitting the pre-amp signal has to meet the input sensitivities of both amps.

You would disconnect your speaker's "split" leads to the bass driver's crossover, and leave the upper driver(s) connections intact to your current amp.

Then, connect your new amp to the bass driver's input crossover. If no input crossover is used, then, connect the new amp directly to the bass driver. How each speaker section, bass and trebles, responds to gain from two different amp's is a balancing trick. The input sensitivity and output ratings of both amps should be matched carefully to even out the bass and treble responces so different levels of gain result in even volume level gains for two different amps.

If bass and treble balance is a problem, I'd consider adding a good quality attenuator or volume controller on the bass driver like a subwoofer's gain is adjusted for different recordings and rooms. A higher end Niles volume controller just before the bass driver connection may do it for you.

If you have enough preamp gain to split your preamp signal, another way is using a Behringer DEQ 2496. One cleanly split preamp signal pair goes to your current amp and treble drivers, and the other split pair to the Behringer's analog inputs. Then, use the analog OUT's to connect to your new bass amps. Connect the new amps leads only to your bass drivers. The Behringer's analog outs/ DAC's in lower frequencies is quite good. It also adds a good volume controller only effecting the bass driver, plus, EQ adjustments. You can use the parametric EQ and adjust +/- any frequency the bass driver reproduces. Then, adjust the main Behringer's main volume to the bass amp.

With the DEQ 2496, you can leave frequency settings to flat (leveraging your internal crossovers)or add in the parametric EQ to your taste. It also has a 12 dB boost to offset marginal preamp signals to better meet the amps input sensitivity.

I'm not a engineer, but tossing ideas out as a consideration.

Maxitonus, your reply is so misleading but obviously your own opinion and from the date saying "about 8 years ago" suggest you owned a very old model.

I own the version prior to the current MK2's as of date and there is no such metalic sound present what so ever you refer to nor the coloured sound so you have left me scratching my head wandering what the hech was wrong with your set-up.

Davidhyman, I had PM'd you previously did you receive. These speakers are true bi-wired but in relation to your question above I do not know because I have not tried and do not know of anyone who has. Possibly ask someone over at MBL but then again they will most likely just want to steer you into using their amps etc.

VAC Statement 450 mono blocks paired up with Vac's Sig. pre are a match made in heaven with these speakers period, nothing else I have heard comes close.
I second Dev advice - the "metalic" only shows in MBLs when they are not properly setup - and this includes improper room acoustics. Some amplifiers, irrespective of power could make them sound also anemic and thin, highlighting their intrinsic colorations.

My experience was with old 101C - and used with the wrong ancillaries they could sound this way. But when everything was perfect they sounded great.

I also was told that current models are much improved in these aspects, but have no experience with them
thanks dev.

what do you mean by PM'd me?

as i said, i ain't giving up the bernings! i gotta make this work or i gotta pass on the speakers.
Soundsbeyondspecs, thank you! i think i get it. i'll have to re-read a few times to fully digest.

make sure my preamp as dual outputs to two sets of amps.

might have to put some variable control between bass amp and speaker.
Davidhyman, private "personal" email. If for example you click onto a membership name a profile page will come up and you will see under the members name (send email) Doing this you can send a personal email.

I did this so you should have one, check your computer.
The power needed for each 'way' almost entirely depends on the crossover frequency.
That is, if on 'normal'.....whatever THAT is, program material you want the amps to redline at about the same time.
Hi dev

I have been trying to send you an email to solicit some advice from you on MBL 101 speakers and amps given your extensive posts on this topic, but I am having trouble with my audiogon account. Audiogon is looking into it Can you email me at so I can get your advice on a few questions? i would really appreciate it

thanks a lot
IS there anyone who can report getting optimal results our of any mbl speaker using a tube amp in any capacity?

I cannot recall having ever read of such.

My understanding is that mbls classify as inherently tube unfriendly. mbl builds SS amps to run their speakers. That alone is a good indicator.

Personally, unless I'm missing something, as a typical consumer, using a tube amp with mbl speakers is not some place I would want to go.

If you like what they are capable of cookin, they are hard to beat set up properly in the right room with the right amplification (SS).

Tube fanciers look elsewhere I would say.
Mapman- Dev's VAC 450's are all tubes. His post is 7 posts ABOVE YOURS IN THIS THREAD!!!! Just pointing this out...... :-)
Ok, i had a feeling i might eat some crow on this one.

If there is a tube amp that can do the job would not surprise me if it were the bigger VACs.
Just a note that I use Conrad-Johnson LP275M tube amplifiers with mbl 101E MK2s and it is mesmerizing!

I also briefly bi-amped with Parasound JC-1s for the woofers and the CJs for the melons.

Good luck!
Actually the mbls are not that hard to drive. 200 watts is plenty of power in most rooms.
"Actually the mbls are not that hard to drive. 200 watts is plenty of power in most rooms."

My understanding is the 101s are capable of prodigious bass and are designed to go into larger rooms to deliver their full potential.

I would expect that a tube amp might not inherently optimally drive the mbls to their max in respect to bass levels due to load, but, in many cases with most rooms, assuming not overtly large, perhaps that could be a non-issue/not matter. And/or perhaps there are ways to tweak impedance matching to alleviate any issues a tube amp might encounter relative to SS driving mbls.

I could see where if maybe if a tube amp were not delivering the meat in the bass as well as a suitable SS amp might enable them to, the other common sonic attributes of the tube amplification might help to still achieve a way above average listening experience with adequate bass for most music in rooms more towards the smaller end for use with 101s. They are in many ways SOTA speakers after all, so they should sound really really good no matter what (with proper setup). The question is always, can they sound better?

OR maybe I am just overestimating how difficult a load mbl 101s would be. I conclude that more by inference based on the fact mbl builds some very beefy SS amps to drive their speakers in the demos I have heard and they just look like they might be a tough load in perhaps some very unique ways given the radical design?

I guess some specs on the mbl 101 load and how that matches to tube amplification would help shed some light.

Also whenever bass levels are in doubt due to amplification and/or other factors, a well integrated sub can usually be made to fill in whatever might be missing, even with mbl I suppose.

Also back to the OPs original inquiry regarding bi-amping, that would involve not using the tube amp for the bass to much greater extent. There would still be a challenge to address I would expect in terms of getting a tube and SS amp (generally different impedance characteristics) to balance properly in a bi-amp scenario. Probably doable, but a challengethat would be addressed through the crossover implementation somehow I would expect. It would surprise me if the internal crossover would handle bi-amping with a tube and SS amp optimally out of the box, but hey you never know what something will sound like usually until you actually try and hear it.

Nsirkin did indicate that his experiment with tube/ss biamping was brief, so I would have to assume that it did not pan out as worth it, at least in his case, so not a good omen there.

BTW, after just noting your current system, jumping from your current tube amp/horn speaker setup to mbl is a BIG change!

Horns and mbl omnis are two opposite ends of the high end spectrum in my book both in terms of how they sound and the kinds of amps that likely work best with each. From there, who knows what other tweaks might be needed to get things tuned in optimally.

SO what I guess I am saying is I guess be prepared up front for the significant investment that might be needed to pull it off in the end both in terms of time and money. And my recommendation is to make sure the 101s are a good fit for your room to start before doing anything. I've heard mbl sound anywhere from stunning to mediocre with the exact same gear set up well at a dealer versus not so well at a show.
Atmasphere, thanks for posting you are most defiantley correct.

I don't know why specific members keep posting on MBL 101E threads and continue to mislead others reading, hidden adgenda for sure.

You can refer to member "Exlibris" whom has been a member since Jan 2005 and has MasterSound 300B 30 watt "TUBE" amps driving his MBL 101E's with great success. You can see his set-up in the "All out assault" section.

Ken Steven's of CAT designed his amps specifically to be paired up with MBL 101E speakers, at this years CES show he showed his $80K Statement JL3 "TUBE" mono blocks paired up with MBL 101E speakers.

A few years ago I had a pair of JL3 Sig. MK2 "TUBE" amps driving my MBL 101E speakers

Currently have VAC Statement 450 mono blocks, dream come true.

Davidhyman it would be very interesting to hear those specific mono blocks paired up with the MBL 101E's, a few years ago I almost bought a pair.

Steve Dobbin's another member has the same amps and drove his MBL's speakers for years.