[guest2521]

Just curious about whether anyone has any experience comparing the bryston st and sst power amps with the pmc variants used in the active setups. PMC modify the amps apparently. Has anyone compared the four variants and do they know what the differences are?

[jethro]

I have a somewhat related question which James will probably have to answer as well:

I bought a used  8B-ST PRO that says "PMC Series" where 8B-ST would normally appear.  Would this have come from an active setup ?

Thanks,

[James Tanner]

The PMC amplifiers are identical to our appropriate models. The PMC Active crossovers we build in the active systems are different from our 10B electronic crossovers.

james

[guest2521]

Hi,

How are the active crossovers different to the 10b? I have the mb2 xbd active. I presume the only adjustment is the three level pots under the face plate, or is more adjustment available inside the casing? I presume if PMC come and set it up for me in my new house then they will just alter the position and the level settings or do they do something else? Many thanks!

Regards,

Nick.

[James Tanner]

^
Hi Nick,

Yes PMC install two more circuit boards which allows for adjustment of low end response and protection of hi-frequency drivers.

james

[guest2521]

Hi,

Would they adjust those during an active install? I presume the normal adjustments on the front of the 10b are hidden inside the pmc crossover? My room is cavernous - its a barn conversion. Any advice on room treatment with regard to absorption and bass improvement?

Regards,

Nick

[James Tanner]

The hi-frequency protection would be set relative to that specific tweeter and system and yes the low bass response would be adjusted relative to specific room nodes.

james

[Mad Mr H]

I have / Have had

3B ST & 3B SST

4B ST & 4B SST & 4B SST PMC Active

7B ST & 7B SST & 7B SST PMC Active


The active remove PMC remove the current limit within the amp and put the limit into the x over.

I was led to believe there were other mods but as I am not 100% sure I wont post "gossip" !!!

The front panel says "PMC Active" & "Engineered by Bryston"


Its 1am here I will go into more detail at the weekend if I can get to  PC.


H.

[Mad Mr H]

I just bought a pair of Bryston X-Overs to turn my BB5's currently run 3 way passive into a full on 3 way active system  aa

Hope to collect them tomorrow 

In a "TRUE" original BB5i ACTIVE cabinet I think the mid driver is slightly different and able to driver harder.

For my use - which is domestic this should not cause an issue.

[Mad Mr H]

ST vs SST

For me the SST series has greater detail, and the mid/hi shows this most.

Other changes are the use of a membrain power switch on the SST series.

Some of the ST series have te delay power on system, The 4B had this towards the end of its run, I had three 4B ST units and one had the delay on system. Not many people use that and it does not alter the audio performance.

I did notice that the SST series can be driven much harder than the ST seres witout hitting the limit "LED".

The PMC "Active" series (in the SST/SST2 for sure) removethe current limit system, this forms the limiter in these amps and is a very sensible feature to have in the amps. In an active system the limiter is placed within the cross over. So although PMC remove it from the amp it is placed elsewhere in the audio path.


I have changed all my ST series to SST series, I would not hesitate to buy the ST series they are excellent, the SS it another step forward and with that comes an increased price tag.

I do not yet own any SST2 series

[drummermitchell]

                                       YET,Mr H,I see it comin .

[Viajero5000]

I just bought a pair of Bryston X-Overs to turn my BB5's currently run 3 way passive into a full on 3 way active system  aa

Hope to collect them tomorrow 

In a "TRUE" original BB5i ACTIVE cabinet I think the mid driver is slightly different and able to driver harder.

For my use - which is domestic this should not cause an issue.

This should be interesting. Are you doing the jobbie yourself?

Btw, having both SST (non- 'choke mod') and SST2, the square takes the extension of the highs and dynamics a step further in my system.

[rahman]

Also interested to see how you get on with the activation job. Best of luck.

Viajero - did you happen to compare a post-choke mod SST with a SST2 by chance?

[Mad Mr H]

This should be interesting. Are you doing the jobbie yourself?

YES

I mean......

NO - My BB5's are only months old so this should only be done by PMC.

You may see pictures of a similar system to mine getting this work done 

[Viajero5000]

Also interested to see how you get on with the activation job. Best of luck.

Viajero - did you happen to compare a post-choke mod SST with a SST2 by chance?

No, never bothered to get my older amp 'choke modded' as i was happy with its sound as it was.  That said, I'm struggling with my set up in my new small room; it's sounding sibilant and painful through the mids and upper mids.  Think I'll have to get smaller speakers till i change my apartment early next year.

[Viajero5000]

This should be interesting. Are you doing the jobbie yourself?

YES

I mean......

NO - My BB5's are only months old so this should only be done by PMC.

You may see pictures of a similar system to mine getting this work done 

haha, ok, I'll look out for photos of the remarkably similar system.

Btw do you know if it's possible to do 'partial activation' of the mb2, using an external cross over for the bass, and leaving the mid and treble hooked to the passive x-over?  This would provide the most material benefits of activation without the need to buy an extra amp and x-over.