[1ZIP]

I have an issue occurring with my setup that is not so much a problem as it is perplexing.  Up until a couple of weeks ago I had a basic BP-26 and was just using 16 gauge zip cord bi-wired.  The volume control at 9:00 was comfortable, 1000 and above was getting a little loud.  Two weeks ago I had the 26 back at service to have the MM phono stage installed.  At the same time I finally decided to upgrade the speaker cable and opted for Furutech U-4.1 T, bi-wired. 

I was astonished at the change, now comfortable listening is just off the peg and 9:00 and above will drive you put of the room.  The change is far from subtle, sound stage is deeper, broader, more and deeper bass, more detail especially in the voice range and better highs.  I did not change any switch settings between the before and after and the change is evident regardless of source.

Although I'm pleased with the current sound there is something unsettling about the change.  Why such a profound difference?  Did modifying the BP-26 change something?  Did the cable change really make that much difference?  Something just doesn't seem right here.

[Napalm]

How long are your cables?

Also since you are bi-wiring, beware that you also changed your crossover parameters. As the cable impedance Z is now part of the crossover network. The changes can be quite serious.

Nap. 

P.S. Remember those cases of surgeons forgetting the scissors inside the patient? Well, there is one documented case of Bryston forgetting a resistor used for testing inside the gear (http://www.audiocircle.com/index.php?topic=5683.0). So maybe they used this opportunity to remove the one inside yours

Just kidding.

Nap. 

[1ZIP]

The cable runs are short, only 10 ft. a side.  Its just that the change is so profound I can't help thinking that something is wrong, especially since the sensitivity of the volume control is so changed!

[Napalm]

The cable runs are short, only 10 ft. a side.  Its just that the change is so profound I can't help thinking that something is wrong, especially since the sensitivity of the volume control is so changed!

10' is long enough. What's the difference in gauge?

You know what - if you really want to see what's up, do a temporary setup with the amp near one of the speakers, connected with a single-wire thick 1' cable, and the other speaker with 10' cable of your choice. Then listen for imbalances in the sound between the channels. With single wire, bi-wire, on the 10' run.

Nap.

[1ZIP]

The old wire was 16 g & I had the speakers bi-wired.  The new cable is 13 ga.

FYI cable info -

13 AWG α(Alpha)μ-OFC Conductor(2.54 sq.mm)for Treble(Blue、Black)
13 AWG α(Alpha)μ-OFC Conductor(2.47 sq.mm)for Bass(Red、White)
Material:μ-OFC

*　α(Alpha)μ-OFC-Conductor---The fine μ-OFC Conductor treated with the α(Alpha) Process (Super Cryogenic & Demagnetizing Treatment)

* Conductor-1:α(Alpha)Conductor,μ-OFC (21/0.15mm+6/46/0.10mm(rope-lay stranding))
* Insulation:Poly Propylene(for Treble，Blue、Black)
* Conductor-2:α(Alpha)Conductor,μ-OFC (7/5/0.3mm(concentric stranding))
* Insulation:Poly Propylene (for Bass，Red、White)
* Sheath:Flexible PVC (Dark Green)
* Overall Diameter:11.0 mm (≒13 AWG) / (2.5 sq.mm)

*Electrical Properties
Max. Conductor Resistance: 10.9Ω/km(for Treble)
Max. Conductor Resistance: 10.20Ω/km(for Bass)
Dielectric Strength: AC 500 V/1min.
Min. Insulation Resistance: 1000 MΩ.km
Capacitance (for Treble): Approx. 70 PF/M
Capacitance (for Bass):   Approx. 85 PF/M



If the the change is due to the Cable I'm going to do some investing, because their on to something!

[Napalm]

The old wire was 16 g & I had the speakers bi-wired.  The new cable is 13 ga.

Capacitance (for Treble): Approx. 70 PF/M
Capacitance (for Bass):   Approx. 85 PF/M

If the the change is due to the Cable I'm going to do some investing, because their on to something!

Capacitance is similar to regular (zip cord) speaker cable so there's nothing special there. Judging by the geometry of the cable inductance should be also in the same ballpark. So what you're probably hearing is the effect of larger gauge (less resistance) . Before any further investment, try with some really thick cable to see what gives. Hint: you can order 9 gauge from Bryston.

Nap. 

[1ZIP]

I think I'm going reinstall the old 16 ga..  If nothing changes or changes little I'll know it's the preamp.  Then it's a topic for Bryston service/engineering to explain.

Thanks

[Napalm]

Please be aware that another thing to consider is the status of the contact of the cable with the connector (banana, terminal post etc.).

When you're replacing old cables with new ones (even identical) you are replacing old, oxidized, loose contacts with fresh, clean, well tightened ones. The difference is not subtle - old, oxidized contacts sound like you have a rectifier diode in series with your speakers. Many people will religiously clean and re-tighten their cables once per year.

Nap. 

[95Dyna]

Please be aware that another thing to consider is the status of the contact of the cable with the connector (banana, terminal post etc.).

When you're replacing old cables with new ones (even identical) you are replacing old, oxidized, loose contacts with fresh, clean, well tightened ones. The difference is not subtle - old, oxidized contacts sound like you have a rectifier diode in series with your speakers. Many people will religiously clean and re-tighten their cables once per year.

Nap. 

Is this condition the same for every source?  If you are only using the phono stage or if it occurs only with the phono stage and not any line level souces maybe the MM stage is set for 41 db which may be too high for your cartridge.  Check the output voltage of your cartridge.  If it's over 5 mV and the MM stage gain is at 41 db that could be your problem.  The MM stage is optimized for 5 mV outputs.  This may be a long shot, however.  I think Bryston sets the MM at 35 db unless 41 is requested.

[1ZIP]

Nap;

I did replace the banana's on the amp & also switched from bare wire connections on the speakers to banana's.

95Dyna;

It's the same condition on all sources.

[95Dyna]

Nap;

I did replace the banana's on the amp & also switched from bare wire connections on the speakers to banana's.

95Dyna;

It's the same condition on all sources.

.....and the plot thickens!   

[James Tanner]

I have an issue occurring with my setup that is not so much a problem as it is perplexing.  Up until a couple of weeks ago I had a basic BP-26 and was just using 16 gauge zip cord bi-wired.  The volume control at 9:00 was comfortable, 1000 and above was getting a little loud.  Two weeks ago I had the 26 back at service to have the MM phono stage installed.  At the same time I finally decided to upgrade the speaker cable and opted for Furutech U-4.1 T, bi-wired. 

I was astonished at the change, now comfortable listening is just off the peg and 9:00 and above will drive you put of the room.  The change is far from subtle, sound stage is deeper, broader, more and deeper bass, more detail especially in the voice range and better highs.  I did not change any switch settings between the before and after and the change is evident regardless of source.

Although I'm pleased with the current sound there is something unsettling about the change.  Why such a profound difference?  Did modifying the BP-26 change something?  Did the cable change really make that much difference?  Something just doesn't seem right here.

Any chance you accidently changed the 'sensitivity' switch on the amp from 2 volts to 1 volt?

james

[rob80b]

Any chance you accidently changed the 'sensitivity' switch on the amp from 2 volts to 1 volt?

james

I was going to mention that but thought I'd give 1ZIP the benefit of the doubt, I've done it myself on occasion.

Robert

[1ZIP]

James;

Nope, both still on 2 volts.

[Napalm]

With stereo setups there's a great rule saying "don't change more than one single thing at a time". 

If you screwed up then for good measure you could also move your speakers a couple of inches and give them some different toe in. For the next 2 months you'll have lots of fun trying to get back "that great sound I had before".

Nap. 

[werd]

Hi

Sounds like they changed the gain in your pre at the shop, to accomodate the phono somehow. I don't think you mentioned your source, was it phono or just any source that these changes were heard?

[95Dyna]

Hi

Sounds like they changed the gain in your pre at the shop, to accomodate the phono somehow. I don't think you mentioned your source, was it phono or just any source that these changes were heard?

See my first post above and 1ZIP's response.

[1ZIP]

Hi

Sounds like they changed the gain in your pre at the shop, to accomodate the phono somehow.

I think it's maybe that plus the new cable and connectors.  I must admit I have no complaints about the new sound.  It's just the change was so dramatic it tweaked the engineer in me to find out why!

[werd]

I think it's maybe that plus the new cable and connectors.  I must admit I have no complaints about the new sound.  It's just the change was so dramatic it tweaked the engineer in me to find out why!

thats good news. My advice is to enjoy that, since real improvement comes few and far between in this hobby imo. Its nice to  plateau in some fashion.