Ron’s New System

[morricab]

20 watts on 84dB sensitivity speakers? I am going to call "no way, Jose!" on that one!

Also irrelevant….the BG driver is much more sensitive and easy to drive than most other planars…except Alsyvox

 

[Alrainbow]

The 75 inchers are nominally 6 ohms (longer than the 50 inch, more impedance), even easier.

Not Easier , what is the sensitivity spec and efficiency
while specs Dont tell all I s a good start
imp alone is not enough to make judgments on Easy.

 

[Alrainbow]

Just what what is it with you an asylvox ?
I’ve heard them on Vox amps small ones and killed in all parameters

 

[cjfrbw]

The pair of 75 inchers I have in hand (Bohlender silver sticker and serial number, identical metal fascia to the Pendragons, not to imply they are the same) are neither difficult to drive nor current hogs like Apogees or Maggies (never owned one).

They measure a flat 6 ohms. In my 19x13.5 ft room with 10 to 15 foo ceilings and a 6x8 dogleg in the high ceiling part, with about a 9 foot equilateral triangle listening arrangement, they sound great with every amp I try on them, from a 45 tube flea to 50 watt Wavac to 20 to 25 watt Pass amps to120 watt AV amp.

The 45 tube amp will show signs of stress with loud orchestral, but from 3 watts up on fleas, I can't perceive meaningful clipping at the volume levels I can tolerate. I am currently running them with my DIY Pass single ended Sony 2SK60 VFET amp (putting out about 8 watts class A into 6 ohms) for several months now, and they sound amazing. Crossover is from 300 Hz to 7Khz. I personally would not want to put a bestial high power amp on them, I have opened them up and they are very fragile looking. I have never seen them moving no matter the volume level.

Believe it or not, low to moderate power amps are what I listen to every day when I am with the system.

 

[Alrainbow]

Ok post the model please
What powers the woofers and tweeters ?

 

[cjfrbw]

There is no model number. The ribbons were purchased from a speaker builder who bought them at the Las Vegas Bohlender Graebener factory close out. I bought them from him

I use and active crossover, and created a kind of hybrid with the 75 inch ribbons and an Analysis Epsilon speaker. Each frequency range have their own drivers and amps. The 75 inch ribbons have their own amp.
The last picture is Pendragon, you can see the fascia look quite similar on the ribbon portion.

I won't post any more on this, its not my thread, but here is a vid I made with 45 tube amp (2 watts/ch) driving the 75 inch ribbons from 300 hz to 7khz:

 

[morricab]

There is no model number. The ribbons were purchased from a speaker builder who bought them at the Las Vegas Bohlender Graebener factory close out. I bought them from him

View attachment 105689I use and active crossover, and created a kind of hybrid with the 75 inch ribbons and an Analysis Epsilon speaker. Each frequency range have their own drivers and amps. The 75 inch ribbons have their own amp.View attachment 105691
The last picture is Pendragon, you can see the fascia look quite similar on the ribbon portion.
View attachment 105692
I won't post any more on this, its not my thread, but here is a vid I made with 45 tube amp (2 watts/ch) driving the 75 inch ribbons from 300 hz to 7khz:

You don’t use the WAVAC anymore?

 

[cjfrbw]

You don’t use the WAVAC anymore?

I have had six amps in rotation for the ribbons, and the Wavac is one of them. Wavac is for lit up, maximum tonal viscosity without losing detail. However, the Pass single ended Sony 2SK60 VFET amp is so good, I have had it in the system for a while. My 45's are at least 15 years old, probably worn, and long in the tooth and are ordinary ebay purchases. 2A3's and 300b's are quite vigorous on the ribbons.
Maybe Gryphon tamped down the sensitivity of the ribbon and added robust ribbon protection in its passive crossover. since they also like monster amps and would, of course, want people to use them on its speakers. I drive the ribbons I have direct.
I think the point is that the ones that I have are not inherently difficult loads by themselves like many current hungry ribbons.
Here's one more vid with the 8 watt Pass DIY single ended Sony 2SK60 (ancient VFET) amp on the 75 inch ribbons. Sorry about the huffing and puffing. Galaxy S8 cell phone recording. For the curious, the You Tube web site has two other vids with same rig playing the more familiar 'Take Five' cuts from Dave Brubeck.

 

[morricab]

I have had six amps in rotation for the ribbons, and the Wavac is one of them. Wavac is for lit up, maximum tonal viscosity without losing detail. However, the Pass single ended Sony 2SK60 VFET amp is so good, I have had it in the system for a while. My 45's are at least 15 years old, probably worn, and long in the tooth and are ordinary ebay purchases. 2A3's and 300b's are quite vigorous on the ribbons.
Maybe Gryphon tamped down the sensitivity of the ribbon and added robust ribbon protection in its passive crossover. since they also like monster amps and would, of course, want people to use them on its speakers. I drive the ribbons I have direct.
I think the point is that the ones that I have are not inherently difficult loads by themselves like many current hungry ribbons.

Probably the passive xover will eat a couple dB. I drove mine active as well and a 30 watt SET was NO problem.

 

[morricab]

Over 112 db on the ribbons alone RMS @350 nominal watts? Issue needs to be called something else rather than clipping.

Will they actually play that loud?

 

[Folsom]

Phil, 213cobra, reported hearing clipping from the amplifiers in triode mode playing Scheherazade at about 85dB. Even I would probably switch to tetrode mode to play big symphony orchestra classical music.

But this is another observation to suggest that my idea about high-powered SETs in the 120 to 140 watt range probably is not realistic l, and probably would go the way of MikeL's Lamm ML3s.

I listen to enough rock and classical that I'm not going want to be switching amplifiers every time I want to play Sarah McLachlan or Stevie Nicks or Jeff Buckley. I'm fine to just push a button and wait 150 seconds to switch between triode mode and tetrode mode on the VTLs.

Phil last night, like Don a week ago, hears with the Pendragons an SET-style sonic benefit of triode mode which neither of them heard on the Magnepans.

So he can hear clipping on tubes? The devices that soft clip? I'd be willing to bet money he hears something entirely different. Audiophiles are wrong typically on these things. They hear IT but what it is, isn't their conjecture.

Thank you, but I would never in a million years try 32 watts on 89dB sensitive speakers. I referred to the ML3s only as an analogy that 140 watt SETs to my speakers would be approximately like ML3s to Mike's speakers.

You could potentially get 104db out of the ML3's. I don't see the issue if it sounds right.

Why would you not try? As was stated it shoukd give you quite loud results before running out of steam, coupled to the fact it won’t have to do bass AND yours is a line source so SPL doesn’t drop as much with distance…you can basically add 3dB for that alone.

Gain is limited by voltage. You don't get extra by removing bass. That also presume the crossover is less of a load than a bass driver/s.

Why? 350 watts into an 89dB line source shoukd not be close to clipping at the levels Ron describes.

350w would be cracking over 113db if they can thermally handle that.

 

[Ron Resnick]

So he can hear clipping on tubes? The devices that soft clip? I'd be willing to bet money he hears something entirely different. Audiophiles are wrong typically on these things. They hear IT but what it is, isn't their conjecture.

I plead guilty to overstating Phil's comment.

I should not have written that Phil "heard clipping." I should've written that Phil heard a "glassiness" which he thought is the kind of sound one hears as an amplifier approaches clipping.

 

[Ron Resnick]

You could potentially get 104db out of the ML3's. I don't see the issue if it sounds right.

This may be some sort of electrical formula calculation for a steady-state 1kHz tone or something. Subjectively, I think it would sound terrible.

 

[Ron Resnick]

Tinka and I had another couple over last night for a listening session. The guests were enjoying Fleetwood Mac so much that they got up and started dancing, so the listening session turned into a dance party!

 

[morricab]

This may be some sort of electrical formula calculation for a steady-state 1kHz tone or something. Subjectively, I think it would sound terrible.

Ron, your driver is basically the closest thing to a resistor as a speaker driver can get. This means impedance is flat and FR is quite flat. So, 89 dB 6 ohms basics applies across the whole driver range. His calculation is every doubling of power adds 3dB to the output. Then taking into account 2 speakers and line vs. point source behavior means that even 10 clean watts will get pretty loud (way over 90dB).

I have a friend who had Octave monos that used KT120 output tubes and these amps also started sounding “glassy” …it is something I have heard in both KT tube types and new tubes (I had NOS GM70s that also sounded glassy the first 50 hours) or both. EL34 and EL84 don’t seem to have this trait even when new…at least not in amps I have owned that used them.

 

[Alrainbow]

Ron, your driver is basically the closest thing to a resistor as a speaker driver can get. This means impedance is flat and FR is quite flat. So, 89 dB 6 ohms basics applies across the whole driver range. His calculation is every doubling of power adds 3dB to the output. Then taking into account 2 speakers and line vs. point source behavior means that even 10 clean watts will get pretty loud (way over 90dB).

I have a friend who had Octave monos that used KT120 output tubes and these amps also started sounding “glassy” …it is something I have heard in both KT tube types and new tubes (I had NOS GM70s that also sounded glassy the first 50 hours) or both. EL34 and EL84 don’t seem to have this trait even when new…at least not in amps I have owned that used them.

On your comments and observations where does dynamics in loudness play a part.
Music is not flat in fact it’s in constant motion of both acoustic watts and electrical watts.
dynamics need a reserve to allow for peaks
Peaks you don’t hear as loudness.
clipping can be heard when bad but to measure at output under load it’s obvious long before you hear it.
set or flea watt demands are real and cannot be judged by speaker specs alone
how far you sit , how loud you play , source used
tape or good analog many times is far for demanding then digital
what Ron has is the best of both worlds
Tubes and dynamic head room to allow music to grow
running out of headroom clips the true peaks
when Ron played that jazz tape the massive yet clean piano strikes seemed complete
bet a tiny amp if used would still sound good but lack the leading Edge and would to use your term flatten the balance needed.
just saying

 

[Al M.]

I have a friend who had Octave monos that used KT120 output tubes and these amps also started sounding “glassy” …it is something I have heard in both KT tube types and new tubes (I had NOS GM70s that also sounded glassy the first 50 hours) or both. EL34 and EL84 don’t seem to have this trait even when new…at least not in amps I have owned that used them.

Same here when I had new KT150 tubes in my Octave RE320 amp. The sound was glassy and kind of "hot" in the beginning. Interestingly, when I switched to new KT120 tubes in the same amp, I did not have that issue. But those tubes were cryo-treated, maybe that had something to do with it, or the fact that the amp itself already had broken in (initially of course both tubes and amp circuitry had to break in).

 

[morricab]

On your comments and observations where does dynamics in loudness play a part.
Music is not flat in fact it’s in constant motion of both acoustic watts and electrical watts.
dynamics need a reserve to allow for peaks
Peaks you don’t hear as loudness.
clipping can be heard when bad but to measure at output under load it’s obvious long before you hear it.
set or flea watt demands are real and cannot be judged by speaker specs alone
how far you sit , how loud you play , source used
tape or good analog many times is far for demanding then digital
what Ron has is the best of both worlds
Tubes and dynamic head room to allow music to grow
running out of headroom clips the true peaks
when Ron played that jazz tape the massive yet clean piano strikes seemed complete
bet a tiny amp if used would still sound good but lack the leading Edge and would to use your term flatten the balance needed.
just saying

I am basing my comments on Ron’s statement that the peak levels were around 90dB. No need for all your speculation unless Ron was way off on his SPL estimate. If the peaks are far higher than 90dB then I would address the issue differently.

 

[morricab]

Same here when I had new KT150 tubes in my Octave RE320 amp. The sound was glassy and kind of "hot" in the beginning. Interestingly, when I switched to new KT120 tubes in the same amp, I did not have that issue. But those tubes were cryo-treated, maybe that had something to do with it, or the fact that the amp itself already had broken in (initially of course both tubes and amp circuitry had to break in).

The best of this type of tube I have heard were NOS 6550s. I put some in a PP KT88 amp I had (PireSound A30) and that was quite good.

 

[cjfrbw]

Will they actually play that loud?

At that frequency range and amp power, they would likely become sparklers.