Unexpected --- Normal?

[pvannest]

Let me start by saying I love my BeePre.  That, coupled with my Eros has brought my system to life on many different levels.  Something that I didn't expect though, was how much louder I can play music without clipping or, at least to my ears, noticeable distortion. 

As an example, in my previous set up I was using an Adcom Preamp feeding my Adcom amplifier.    When playing music that had a wide dynamic range, I would quickly hit the clipping point.  (Note: I do have some hearing loss due to a little mishap with some home made fire works in Tianjin so I admit that I play the music a tad too loud.)

Anyway, a good example of this would be when playing the Good Vibrations cut on Telarc's Omnidisc.  I would have to turn down the music so low that I could hardly hear it with the old set up.    If not, the resulting distortion was unacceptable.    Now, with the Eros and Beepre, I can play is much louder with no noticeable strain.    I have been trying to figure out why.    My guess would be since there is a much stronger signal being fed to the amplifier it doesn't have to work as hard for a given output to the speakers.    I find that hard to accept though since the speakers should start clipping at the same voltage level regardless of what is fed into them.  Could it be that the Adcom preamp was the fly in the ointment so to speak?

Any other ideas?       

 

[Doc B]

(Note: I do have some hearing loss due to a little mishap with some home made fire works in Tianjin so I admit that I play the music a tad too loud.)

That reminds me of the night that someone sent Jacqui Naylor their regrets that they couldn't make it to her show due to a 'skydiving incident'.

 

[pvannest]

Believe me it was a bit of a scare.  I was totally deaf for about a half hour....  One very big fire cracker at my feet. 

 

[mcandmar]

Believe me it was a bit of a scare.  I was totally deaf for about a half hour....  One very big fire cracker at my feet.

That does not sound pleasant at all :-\

In relation to your first post, i always found SS amps have a very limited range of what they will take in, and amplify out before they start to clip.  In my very limited experience with valve amps they all seem to pass my pain threshold before starting to noticeably clip or distort. I'm sure there is a very simple explanation to do with voltage swing ranges etc..

 

[mcandmar]

(Note: I do have some hearing loss due to a little mishap with some home made fire works in Tianjin so I admit that I play the music a tad too loud.)

That reminds me of the night that someone sent Jacqui Naylor their regrets that they couldn't make it to her show due to a 'skydiving incident'.

I've just realized who you are talking about as i'm listening to the Best of Audiophile Voices at the moment, its my goto album anytime i make any changes (just built a quickie).  "Ain't No Sunshine" by Jacqui Naylor is one of my favorite tracks, i had one of those weird i've heard that name before moments when it started playing. I really should buy an album and have a listen..

 

[Doc B]

Are you sure? I see a cover by Eva Cassidy in that series, but I wasn't aware that Jacqui had licensed anything to Top2 Music. She did cover the song on You Don't Know Jacq

 

[mcandmar]

Are you sure? I see a cover by Eva Cassidy in that series, but I wasn't aware that Jacqui had licensed anything to Top2 Music. She did cover the song on You Don't Know Jacq

Positive, track 10.  http://www.wowhd.co.uk/CD/various-best-of-jazz-audiophile-voices-2cd/dp/24708107

Sorry for the thread derailment pvannest..

 

[Doc B]

Interesting, thanks. Gets me thinking of what track of JQ's I might have put on an audiophile sampler. If you want to buy a CD of hers I would suggest the recently released Dead Divas Society, Lucky Girl and Live East West as good ones to start with.

OK, back to Bee Pre...

 

[Paul Birkeland]

My guess would be since there is a much stronger signal being fed to the amplifier it doesn't have to work as hard for a given output to the speakers.    I find that hard to accept though since the speakers should start clipping at the same voltage level regardless of what is fed into them.  Could it be that the Adcom preamp was the fly in the ointment so to speak?

Any other ideas?     

I think there's some logic to your reasoning, as you removed the Adcom preamp and somehow your system opened up a bit.  Solid state components do also wear out and drift, and it's possible that you simply had some worn components in the Adcom preamp that weren't performing up to snuff. 

On the amplifier end, you have a very sensitive amplifier and very sensitive speakers, so the actual drive capability of the preamplifier should be largely unimportant.  There's a slight chance that the Adcom amp has low input impedance, and that worn components in the preamplifier were limiting current delivery from the preamp, inducing distortion in the output of the pre.

All of this is pretty speculative until you get a scope or spectrum analyzer and start inspecting each component in the chain.

 

[pvannest]

My guess would be since there is a much stronger signal being fed to the amplifier it doesn't have to work as hard for a given output to the speakers.    I find that hard to accept though since the speakers should start clipping at the same voltage level regardless of what is fed into them.  Could it be that the Adcom preamp was the fly in the ointment so to speak?

Any other ideas?     

I think there's some logic to your reasoning, as you removed the Adcom preamp and somehow your system opened up a bit.  Solid state components do also wear out and drift, and it's possible that you simply had some worn components in the Adcom preamp that weren't performing up to snuff. 

On the amplifier end, you have a very sensitive amplifier and very sensitive speakers, so the actual drive capability of the preamplifier should be largely unimportant.  There's a slight chance that the Adcom amp has low input impedance, and that worn components in the preamplifier were limiting current delivery from the preamp, inducing distortion in the output of the pre.

All of this is pretty speculative until you get a scope or spectrum analyzer and start inspecting each component in the chain.

Actually when you consider the age of the amplifier, that may make sense.  It is about 25 years old and due to be replaced by Santa in the next few weeks.    It will be interesting to note what differences I will experience with the new amp.  I will update this thread at that time to let you know.

 

[Analogluvr]

I have noticed the exact same thing. I just completed a Beepre and am enjoying it immensely. It is feeding we91b clones or sophia 845s. It kicked an already very good vacuum state pre to the curb. Previously with the vacuum state I noticed I would get a little crackle in my ear with high volume passages but now I dont get that even at louder volumes. I was putting se thought into that I think it's the set sound. It's the lack of higher order harmonics(distortion) which we use to perceive as loudness cues.  That's my thoughts.
Anyhow I love it!!

 

[Johnny2Bad]

I can propose a potential explanation for what is happening electronics-wise as well as sonically.

Firstly it probably comes as no surprise to Bottlehead forum members and owners that vacuum state electronics differ from solid state electronics in their overload characteristics and tendencies. Specifically, tubes can swing a lot of volts in comparison to ss small-signal devices.

But how can that in turn result in a cleaner overload character? One at first assumes that the power amplifier has a certain sensitivity and a certain output power at the onset of clipping. We test power amps for these very characteristics and conclude the power output specification from them.

Let's assume that no genie arrives in the sound room and the mere presence of a Bottlehead preamp in place of a different Solid State (SS) preamp does not change the steady state power output of the power amplifier, nor does it affect the transient state (dynamic "music power") capability ... if the power amp was capable of clean transient output in excess of it's steady state (sine wave) output, that nothing changes here and the same short term ability remains unchanged.

However we do need to assume there is some ability of the power amp to produce good transient behaviour. Some amps are good for so many watts, fast or slow, and that's that. We are assuming that we are not running such a power amp.

What, then, of the preamp's transient abilities? There exists some (not enough, unfortunately) evidence from testing that vacuum state small-signal and power devices can swing significantly more voltage in short term transient signals than even the already impressive overload characteristics of a typical tube preamp. I've seen some where the output of a tube amp can be 3 or even 4x the sine wave pre-clipping output over very brief periods.

Now, this is not a unique feature of VS (Vacuum State) small signal components ... SS preamps also have transient abilities. It's just that the SS devices tend to be on the order of 2x or less than the steady-state output abilities.

I think your Bottlehead is throwing a lot of clean power to the power amp, the power amp is capable of dealing with it cleanly provided it's not too long or doesn't repeat too fast for the power amp's power supply to recover, and this is in contrast to your old preamp that would not be able to do the same.