BEL 1001 MK5 driving Joseph Audio Pulsars

I own the BEL amp and considering the purchase of a used pair of the Plusars.

My concern is the Pulsars 83.5 dB sensitivity as measured in Stereophile.  They do have a benign impedance curve, not dipping below 6 ohms. This to me means a speaker that thirsts after watts as opposed to current. 

The BEL is rated at 50wpc into 8ohm and doubles down into 4 and 2 ohm loads, likely due to a very conservative 8 ohm rating. Easily drives my Esoteric MG10s (87dB sensitive, 6ohm nominal impedance) to very loud levels.

My room size is `12.5 by 14.5 x 8.5 feet.  An asset for speakers of low sensitivity.

I am looking for thoughts regarding the BEL's ability to drive the Pulsars in a modest size room.

They should work well together in your size room.  There's a follow up to the original Stereophile review where it's used successfully with a 25 watt amp.
I have a pair of Pulsars (v1). Jeff Joseph told me directly that an amp of at least 60 wpc should be used with them.
Should be fine.  Bigger question is if they’re a good sonic pairing with the Pulsars. 
That is about as big a room as I would attempt to use. 83dB is is *very* low sensitivity! How old is the BEL? If older than 25 years, you really might want to consider getting the filter capacitorss in the power supply replaced. It will sound better, and the danger of destroying the power transformer due to bad filter caps will be gone for another decade or two.
Thanks all!  I consider the BEL to be borderline in wattage. It is a brut for a 50 watter however.  

If I indeed purchase the Pulsars, I will approach the volume with caution. 

My BEL was made in 2007, so not long prior to Mr. Brown passing away. I intend to have someone put it on the test bench one day and have those big caps replaced. 
in a modest size room at reasonable volume levels the bel shd be fine

84 db w m is purdy low though... 
What would be great is to find another 1001 Mk.5. Running a pair with each as a mono amp significantly increases not just their power output (quadrupling it!), but their sound quality as well.
Yes, If I could find another BEL of recent vintage at the right price. 

I am really on the fence on this. I have been wanting to hear the Pulsars for some time and am now in a position to 

Ha, I left you hanging...  in a position to purchase a pair to try out and I find myself thinking about going in a different direction speaker wise. Ones that are higher in efficiency, which means for me benign impedance and high sensitivity.  That way I could try a tube amplifier if I choose. ( I run a tube preamp with the BEL.) Just that I have always been a fan of stand mount 2-ways for a small room. Not many meet the efficiency criterion. 

The Pulsars I am considering are on offer here at AG. I made an offer and received a counter which gives me a day to consider my options.  If they get sold in the meantime, congrats to the seller. If I accept the counter the Pulsars could always be resold.  I will keep you informed. 


if you are buying at the decent price you can always resell at or near that cost

part of the fun of all this is trying what you think may be good, then finding out for yourself, in your own syste,

way too many keyboard jockeys here that read commercial reviews, watch some youtube videos and the like, get all in a tither then come here spew their nonsense without really knowing without really hearing for themselves
2007 is probably not old enough yet for the power supply caps to be in trouble.
Yes jjss49, I tend to agree. It will be the 1st time I buy a speaker I havn’t heard. 
Well after much deliberation I have decided to pass on the counter offer. Think I may wish to go in a different direction with speakers. 
Thanks all for your thoughts.

I became more concerned about the very low sensitivity. I believe a amp as good as my BEL but with higher wattage would be overly expensive for my budget.

3 grand and up is alot of money to spend on speakers... so many very nice sounding ones to choose from esp. if you entertain well cared for used ones

u have not mentioned what kind of music you listen to...  you seem to know what to target in your search but as you know this forum is just full of ideas .... :)
The genre of music makes no difference. If anyone could find a way to make a speaker or electronics favor a certain kind of music they would be a millionaire overnight :)

ralph/atmasphere’s comments notwithstanding

i stand by my post

some speakers are definitely better suited to some genres (and usual implied volume levels) than others... in my experience knowing what music you mostly listen to helps tremendously in picking the right speakers

Whether or not any given speaker "favours a certain kind of music", there are certainly examples of speakers that are poor choices for certain kinds. A mini monitor (or the QUAD ESL) for reproducing pipe organ recordings (a Symphony Orchestra performing, say, Berlioz Requiem, such as Colin Davis conducting The LSO. Or Saint-Saens Symphony No. 3 by George Pretre and The Paris Conservatoire Orchestra with Maurice Durufle on organ. Or AC/DC’s Back In Black ;-) played at live listening SPL. Another reason to buy a DBA!

One who listens to predominantly acoustic Folk (or Bluegrass) music may not need the same "kind" of speaker as does one who listens to Death Metal, just as a driver who travels on only highways doesn’t need a car with the same abilities as does the driver who spends time on winding mountain roads. It’s the ol’ sports car vs. tractor scenario. Horses for courses: It’s not only what a speaker can do, but what it can’t. Different musics certainly DO place different demands on loudspeakers, which reward the musics accourding to their strengths and weaknesses (or abilities and inabilities). IMO ;-) .

Yes, a perfect loudspeaker would be able to reproduce all musics equally well. Since there aren’t any, and since different speakers have different imperfections (or inabilities), does it not make sense to choose one whose abilities and inabilities align well the demands the music the listener is most concerned with places on the speaker? You can’t have it all, though the "best" speakers may come closer than more compromised ones.

What abilities are most important to you? What are you willing to give up in order to get something else? I can’t live with a speaker exhibiting ANY vowel colorations (the great term coined, as far as I know, by J. Gordon Holt), And I need a speaker which can reproduce the contrasting timbre of the harpsichord, cello, violin, and flute playing J.S. Bach, revealing the very complex (and changing) root/harmonic overtone structure each instrument produces (speakers vary DRASTICALLY in their abilities to do that). But pinpoint imaging and a great soundstage are not that important to me. To each his own!

Driving a pair of Pulsars (ver 1) with a pair of Mr. Karsten's Atma-Sphere M-60 mono amps (luckily thru one of his pre-amps!) in a room of the exact same dimensions described.

My tastes vary, Radiohead to Dinah Shore to Debussy to Iron & Wine, etc. etc., all in one day. On no occasion have ever felt the 60 watt amps were not enough. They can take Mighty Sam McLain's 'Too Proud' to the point where my living room windows are actually rattling (hard to believe the little Pulsars can move that much air, yet somehow they do...), and I still don't think I've tapped out all the M-60's have to give. You just wouldn't want it any louder.    

Have no experience with the BEL, but if is the solid 50 wpc I imagine it to be, I suspect you'll not want for more, less you're keen on deafness;).
And there’s a pair of Pulsars in beautiful sapele wood finish available here for $3300.  Just sayin’. 
A speaker in the 83-84 db range, is certainly going to tax any amplifier, if truthful dynamics is expected. I agree as well, the music, listening room / listener distance, volume levels, etc, all play a big part. My speakers play with any amplifier made ( modified / tweaked Lascalas ), and they do everything I find most important, with my music and in my room. That is a wonderful thing. I say stay away from very inefficient speakers.
I say stay away from very inefficient speakers.

having been there and done that a couple times in the past, i now do too...

just like heavy automobiles... they can work fine and be very good, but heading in the opposite direction just has too many inherent advantages
The BEL is a fantastic amp and is known to be subjectively more powerful than its rated 50 watts, so unless your listening proclivities lean toward high volume levels you should probably be fine. Of course, bdp24’s suggestion regarding obtaining a second unit and running them as mono blocks is spot on and would erase any doubts whatsoever.
i stand by my post

some speakers are definitely better suited to some genres (and usual implied volume levels) than others... in my experience knowing what music you mostly listen to helps tremendously in picking the right speakers
The volume level and the ability to play bass might be the only possible ways a certain speaker might favor a certain genre. But beyond that, the idea is actually the most prevalent myth I've run into in the audio world. If a speaker plays bass well, its good in that regard for metal, rock, classical and jazz, as all genres sooner or later have bass and some of it can be quite deep and powerful, In that regard, bass has often all about budget, but the recent addition of the Audiokinesis Swarm to the audiophile toolbox has reduced that significantly.
The only other issue is volume level, again dictated more by housing constraints and budget. I do find that lower efficiency speakers are less able to play dynamics due to thermal compression but beyond that what makes a speaker great for rock, metal, jazz, folk and the like also makes it good for classical, downtempo 80s, electronia and the like. My taste is in all of these areas and I play them all at audio shows.

I've had many disagree with my about this myth but that is simply a measure of how well it has propagated. I think the classic example has been JBL L100s and rock. While many that like rock have used L100s, JBL would be able to sell it all that well if that speaker only played rock correctly. Not all rock is recorded the same way; rock has a history that covers over 60 years; in that time how its recorded has changed drastically... 

The L100 is a good example. Hearing it when it was first introduced, and having already developed a high sensitivity to loudspeaker coloration, as well as a love of vocalists and harmony singing, I knew I could never live with the L100. It’s reproduction of voices was atrocious!

For one who listens predominantly to instrumental Classical and/or Jazz, the vowel coloration of the L100 may not have been as objectionable. Yes, it was still introducing the same coloration, but we all know what the human voice sounds like; recorded instruments, not necessarily. Vowel coloration added to a tenor sax (which I have myself recorded, with a good quality condenser mic straight into a Revox A77) is not as noticeable (and objectionable) as is that same coloration added to a voice. IMO.

A loudspeaker which is good at revealing the inner detail in recordings will allow one to hear more of that detail than will a speaker which is mediocre in that regard. I know, of course. But if you listen to music which doesn’t require that ability as much as do some other musics, you won’t miss it in a speaker which doesn’t provide it. It’s not a matter of a speaker being able to play all music equally well, but rather a matter of one speaker being able to do more of what you want or need it to do than will another.

All loudspeakers are the end result of numerous choices, of trade-offs and compromises, the designer going after what he values most in music reproduction (or thinks the marketplace does ;-). The trick is finding one whose compromises produce a sound that aligns with your musical desires and/or needs.

But if you listen to music which doesn’t require that ability as much as do some other musics, you won’t miss it in a speaker which doesn’t provide it.
I really don't know what music that would be! The human voice tends to show up in every genre I've encountered so far. I think in the reissue of the L100 they fixed that peakiness of the original.
The BEL amps are kind of "underground"... What is a reasonable price for a Mk V?  Mk IV?

you are a longtime owner of the bel 1001 mk5? that is one legendary amp i have always been curious about but never actually had one

is it in the pure and clean school of ss amps or more warmed up and fattened a touch like pass or better hegel? based on reviews i am under the impression it is more in the former camp
@macdonj  I believe the price would reflect age. My amp was made in 2007. Retailed at ~$4000 then. If I were to sell mine I would likely ask $1200. One BEL 1001 recently sold on AG for $1125, I am not clear on which MK it was.

@jjss49  I have not directly (in my home) compared my BEL to other amps. Had experience with a Classe 101 which I thought was detailed to the point of being clinical, too lean for my taste.  The BEL seems pure and clean but not to the point of being lean, yet provides bloom but not to the point of being overly warm. I would describe it as detailed yet smooth. I have used this amp for 8 years driving a pair of Esoteric MG-10s, 7" standmounts, and now with Tannoy Sterlings which are quite different. The BEL plays well with both. I am sorry that I can't better respond to your question, haven't developed my audio prose to any elaborate extent. I do enjoy your contributions across this forum.
Thank you @mesch.  I suspected used prices would be close to what you posted. It's a shame these aren't being built anymore.
Definitely keep the BEL.  I owned one for about 20 years and wished I never sold mine.  I still look periodically for  Mk5 and would purchase it immediately if it popped up.  As you know the key is finding the right speaker match.
@bobheinatz  Yes, I plan on keeping mine for a few more years. This after considering replacing it and deciding that I have no idea what amp I would replace it with. Was thinking a Pass XA25. Also was considering returning to an integrated amplifier. 

Now keeping myself in a holding pattern. Maybe do a couple touch-and-goes.