[Bob Reynolds]

Bryston BP-26 vs Pass Labs X1
Sighted Level Matched Comparison

August 12, 2006

Associated Equipment
--------------------
Arcam FMJ CD23T CD player
Bryston 7B-SST monoblock amplifiers
M&K LFE-4 bass management controller
M&K S-150 Reference Monitors
M&K MPS-5310 subwoofer

Music
-----
Louis Armstrong & Duke Ellington: The Great Summit - The Master Takes
Tracks 1 - 4

Measuring Equipment
-------------------
Fluke 112 DMM
Track 3 of M&K setup CD (1 KHz sine wave at -20 dBFS)

Setup Procedure
---------------
1. Using X1, play track 1 of LS&DK to determine acceptable volume level. This turned out to be 13.

2. Using X1 at level 13, play M&K track 3. Measure voltage at binding posts of left speaker. This value was 0.48 volts.

3. Using BP-26, play M&K track 3. Measure voltage at binding post of left speaker and adjust volume to be as close to 0.48 volts. This value was 0.481 volts.

4. Thus, the volume levels between the two preamps were matched to within 0.018dB.

Comparison Procedure
--------------------
1. Using X1, play tracks 1 - 4 of LS&DK and note any special characteristics.

2. Using BP-26, play tracks 1-4 of LS&DK and note any special characteristics.

3. Discuss observations.

4. Repeat at step 1.

Observations
------------
After the first iteration of hearing both preamps, both participants agreed that the two preamps definitely sounded different. We agreed that the differences were highlighted at the frequency extremes. We both agreed that the X1 sounded more rounded and the BP-26 sounded cooler. Brass horns sounded more metallic through the BP-26. The bass line through the X1 seemed to be more apparent. We disagreed on which preamp was more detailed or revealing. We both agreed that the BP-26 was probably the more accurate.

After the second iteration, things got very strange. Characteristics that were attributed to one preamp were now being attributed to the other one. The differences between the two preamps began to blur.

We did not have time to continue the process.

Conclusions
-----------
The exercise convinced me that both preamps are much more alike than different. That our initial listening iteration was probably biased by preconceived notions of how the preamps were supposed to sound. That the second listening iteration was probably much more indicative of reality. That under blind conditions with 20 iterations, no one could identify either preamp with any degree of certainty. That doing a valid blind level matched comparison is a lot of work.

[John Casler]

I know the MSRP of the BP-26 is $3195.  What was the MSRP on the Pass model you compared?

[Bob Reynolds]

I know the MSRP of the BP-26 is $3195.  What was the MSRP on the Pass model you compared?

Hi John,

The Pass X1 model I bought, which has now been replaced with the BP-26, was the "hybrid", i.e., older cosmetics power supply box. I believe the pricing of the Pass X1 breaks down as:

1. the current Pass X1 lists for $5900,

2. the original Pass X1 (plain Jane power supply box) listed for $5500,

3. the current Pass X1 ("hybrid", plain Jane power supply box) lists from $3700 from Audio-Video Logic.

It is claimed that the active circuitry preamp box is unchanged from the original X1; only a matching box for the power supply was changed. The hybrid is built to order by Pass Labs and shipped direct to the customer.

I think this points out that the Bryston BP-26 is an excellent value and most likely the point of diminishing returns for preamps.

[tonyptony]

Bob, this sounds correct. The Pass X1 with its older power supply (only cosmetically different from the new supply - I confirmed this by speaking with Wayne at Pass Labs) is actually available for about $3K. At that price it could be considered a bargain.

I have the X1. Have heard it along with other preamps in my system. Not sure about "rounded". It is certainly not etched or "cool". Taking system dependency into account, I have found that with the X1 in my system what I hear sounds closer to the real thing than many other preamps I've tried (I go to on the order of 20 symphonies and jazz concerts a season). Wondering what the BP-26 would sound like in my system; have heard a number of good things about it.

[warnerwh]

Thank you for this comparison and your objectivity. I'm sure Bryston has an advantage of making alot more preamps than Pass hence the better price. I'm sure both are excellent though and to do better would be very expensive as both are at near state of the art.