BrianGT Basic vs Premium+BG Test part 1

[Vikash]

A friend and I did some listening comparisons between Brian's basic and premium kits. The premium kits have 1000uf BG caps instead of the Panasonics.

Neither of us knew which amp was being used at any time. The source and pre used was a Shanling CDT-200 and the speakers were Martin Logan Scenarios. Both amps have been running for no more than 5 hours total since being built (thus part 1 of the test).

Both are power amps (no pot/attenuator), and the only addition to the kit circuit is a 680ohm resistor parallel on the input (standard 1% resistor) to reduce DC offset.

I'll keep it short:
We were hard pressed to find any difference between the amps. After some hard listening we were eventually presented with a subtle difference, but we both felt slightly different about it. Before unmasking the amps identities, I sincerely could not choose which I thought was the better amp, describing what was to be the basic amp as laid back, and the premium as more bodied but a little harsh at times. My collegue chose the basic amp and described it simply as being more open. He wasn't suprised at the unveiling and said simply that the BG's are notorious for requiring time to burn in.

The ML scenarios are incapable of any real low end, so I'll be doing this again after some run in time and using the bigger ML Ascents.

I have to conclude by saying that it is not easy to tell these two amps apart. Perhaps some running in will allow the premium kit to shine out more, but for now I feel that it's far from being superior to the basic kit, regardless of the cost.

[Upupa Epops]

What you was awaiting ? Differences will be probably only in psychoacoustic region .

[carlosfm]

Wanna hear real differencies?
Take one of the amps and do this:

- Invert
- Buffer
- Regulate

[ofb]

if you'd like to push the BG's along, you could try rjm's cap rack.

http://www.geocities.com/rjm003.geo/.../diy_rack.html

[Variac]

I think this is a good constructive thread.
Kind of a no-evil analogue to what is happening on the Randi 1M thread.

In this case someone is taking advantage of the fact that a premium Brian GT clone is still pretty cheap so it affords the luxury of actually listening for differences. Why aren't more people doing this instead of just arguing the point?

Carlos: I guess you have to send them your amp to compare also! After all the UK is only a few mile north of you!
Otherwise you can't be sure they made it right!
I'm sure they wil take very good care of it. Also, you probably are making another anyway!

[Peter Daniel]

Originally posted by Vikash
Both are power amps (no pot/attenuator), and the only addition to the kit circuit is a 680ohm resistor parallel on the input (standard 1% resistor) to reduce DC offset.

Perhaps removing those resistors would change things a bit. Do you really need them?

[carlosfm]

Originally posted by Variac
Carlos: I guess you have to send them your amp to compare also! After all the UK is only a few mile north of you!

I'll go by bike.

Forget it, I was joking, just a suggestion to listen to real different amps.

[Vikash]

Why aren't more people doing this instead of just arguing the point?

I find this frustrating too. Some people just enjoy the debating more I guess.

I should probably have left those resistors out for the test. I'm ordering some caps to try out Ci on the National schematic to reduce offset which I'll try and put in after then next test.

See attached in case you change your mind about the bike ride Carlos.

These amps are excellent in their own right and they've shown up many recordings, whilst allowing the good ones to sound spectacular. This is all further highlighted by how little they cost. I can't see why I would ever purchase a commercial amp again.

[Vikash]

Originally posted by ofb
if you'd like to push the BG's along, you could try rjm's cap rack.

http://www.geocities.com/rjm003.geo/.../diy_rack.html

Interesting but I don't know how often I'll be running in caps though

I've just connected the input between both amps together and stuck 8ohm resistor on each output. I'll just let it play like this for several days.

[percy]

Originally posted by Variac
Why aren't more people doing this instead of just arguing the point?

Originally posted by Vikash

I find this frustrating too. Some people just enjoy the debating more I guess.

Vikash, your efforts are indeed highly appreciated, however....

Vikash/Variac,
You have to understand that this is a 'discussion' board. There are ought to be more debates and discussions than actual tests and results!! And not all of us have the liberty and privilege of funds and fancy test benches and instruments and Martin Logans and Shanglins, hence they turn to the board with their questions and try to find an answer.

Also, there is no point in reinventing the wheel, hence the discussion/debate to find out whether it has been done before or not, naturally comes first.