Headphone gain on BP25

rob80b · « **on:** 26 May 2006, 07:37 pm »

Just picked up a mint BP25P (02/04) to replace my ageing but still excellent .5.
The main reason for picking up the BP25 was for the remote and headphone out to replace my Creek OBH-11se Rev B headphone amp.
The problem I have is that the headphone output is extremely low even with my Grado SR325i’s, the volume needs to be at about 3 o’clock, my Senn 580’s and AKG 501’s are almost non usable. This creates a problem if someone disconnects the phones without lowering the volume, a likely occurrence.
With the Creek and other amps I’ve used, the nine o’clock position is more than sufficient with the Grado’s, 11 o’clock with the Senn and between 12 and 1 for the AKG’s.
So the question is do all Bryston preamps have such a low gain on the headphone out.
Also even on speaker playback the BP25 is at about 12 o’clock while the .5 was at about 9 o’clock to run my Dynaudio Contour’s off my 3BST at fairly loud levels.

gaderson · « **Reply #1 on:** 26 May 2006, 11:15 pm »

Strange, I've been able to keep my volume at 12 o'clock for both my phones (Senn HD580s with Grado extension), and my monitors (PMC DB1Ss power by an 4B-ST Pro). But, with the Pro I can adjust the gain on my 4B (currently at lowest setting, but, still I've found plenty of gain for my cans. This is mostly using my MOTU Traveler from my Mac as the main audio source--balanced TRS->XLR. I do have to turn things down for my Sony DVD player. It's great for my monitoring uses.

rob80b · « **Reply #2 on:** 26 May 2006, 11:29 pm »

Doing my homework before picking up the BP25 pointed to it being a very good headphone amp with no reference to lack of volume.
I've sent a note off to Bryston, so hopefully I'll find out soon.
In the meantime I will keep my Creek OBH11se which does a stellar job at driving all my phones.

rob80b · « **Reply #3 on:** 27 May 2006, 09:29 pm »

Interesting, after letting the preamp warmup for 24 hours there appears to more gain, even enough to drive the K501's, but we are still talking 3 o'clock on the dial.
A little dangereous if the phones are pulled without lowering the volume first
( I have a 7 year old who loves music)
Soundwise the headphone output is excellent though.

rob80b · « **Reply #4 on:** 30 May 2006, 01:08 am »

Sorry if I’m almost carrying on a monologue here, but after 3 days burn in I can happily report the gain has increased again, for the phones and speakers.
Grado’s and Senn’s are running around 12 o’clock and the Akg’s around 2-3 o’clock on the dial. Reasonable
Also listening to my Dynaudio Contours the sound has opened up immensely, For the first two days I had my doubts and was about to re-install my Bryston .5.

gaderson · « **Reply #5 on:** 30 May 2006, 08:19 am »

Quote from: rob80b

Sorry if I’m almost carrying on a monologue here, but after 3 days burn in I can happily report the gain has increased again, for the phones and speakers.
Grado’s and Senn’s are running around 12 o’clock and the Akg’s around 2-3 o’clock on the dial. Reasonable
Also listening to my Dynaudio Contours the sound has opened up immensely, For the first two days I had my doubts and was about to re-install my Bryston .5.

Interesing, I guess I keep mine on most of the time, but, I did get mine used, so maybe it really was burn-in. But, still seems strange. I also leave the headphones attached, and just mute un-mute as needed. Wonder if the extra impedence is something?

rob80b · « **Reply #6 on:** 30 May 2006, 01:46 pm »

Quote from: gaderson

Interesing, I guess I keep mine on most of the time, but, I did get mine used, so maybe it really was burn-in. But, still seems strange. I also leave the headphones attached, and just mute un-mute as needed. Wonder if the extra impedence is something?

My equipment is always on 24/7 unless I'm on extended vacation, but this a new piece so hopefully she’s bedded in now.
Do you have an earlier BP25, because I cannot have the phones and the speakers on simultaneous. Once the phones are engaged they mute the speaker outputs so I have to unplug them each time, a real pain.
I would love to have a three way switch, Headphones, Headphone/Speakers, Speakers.

rob80b · « **Reply #7 on:** 3 Jun 2006, 08:12 pm »

Here's some info from the original 12B manual

“ Since some headphones may require substantial volume control rotation, be sure to reduce the volume before removing the headphone plug, or you may be startled by the high sound level when the relay re-connects the amplifier”

As a frequent headphone user other family members may not be as courteous in following the rules, least you forget.

PorkpieHat · « **Reply #8 on:** 5 Jun 2006, 09:35 am »

It's not break-in. I have the same problem with my BP25. If there's a fix, I'm going to be all over it.

rob80b · « **Reply #9 on:** 5 Jun 2006, 12:55 pm »

Bryston got back to me saying that the overall gain of the preamp can be increased but not just the headphone output.
Which leaves us in the same position, the volume will always be higher set for the phones than the speakers.
I was hoping it was just a matter of changing the output resistance (resister) of the headphone output.

rob80b · « **Reply #10 on:** 5 Jun 2006, 05:04 pm »

Well it happened, my son disconnected the phones while my CD was on pause and then I returned to the piece by George Crumb I was playing and bottomed out my Contours pop-pop- pop, and that’s with them crossed over at 80hz with the Velodyne.
They seem to be okay though.

elcaptain88 · « **Reply #11 on:** 5 Jun 2006, 09:18 pm »

I used to have a B-60 and have used a BP-25 and can relate to your issues as I am an avid headphone user. I have since switched to a Van Alstine Ultra SL preamp which has a much better (to me) headphone output with no volume issues. The Bryston was a very good preamp though. If you need a unit for both preamp and headphone duties I would strongly recommend comparing the two.

rob80b · « **Reply #12 on:** 5 Jun 2006, 10:50 pm »

Actually I was happy with the Bryston .5 and the Creek OBH-11SE, with the BP25P I was hoping to simplify my setup with the extra bonus of remote volume.
I'm still coming to terms with the BP25, I find the .5 to be more musical, but then I've had it since 1989/1990