[rob80b]

2BLP Pro as a head-amp Revisited..again.

Sometimes you cannot get enough of a good thing, this past summer thinking my BHA-1 would handle all my headphone listening I sold my last and latest version of the 2BLP pro from 2001, only to regret it once I picked up another pair of AKGs the K712s.

Unlike my previous K701s and K501s, the 712s have a 3 pin mini xlr and need major surgery as to take advantage of the increased gain available from the balanced outputs of BHA-1 so what’s one to do, why pick up another 2BLP pro as it worked great running off the balanced outputs of the BHA-1 to power my previous K701s and the AKG K501s.

Well a few interesting hours doing some comparisons between the stand alone BHA-1 and the BHA-1 as a pre for the Bryston 2BLP pro…………
 

Unlike the earlier 2BLP pros, although still using the same it not identical circuit but with updated components, I find the current renditions much quieter and as where my last one manufactured in 2001 had some residual noise with the volume controls maxed out, although way above safe listening, the current one I’ve just acquired (thanks Servingko) dating from 2002 only has a very slight hiss…again only when the BHA-1s volume and the 2Bs pots completely open.



And in all honesty... with the BHA-1 used as a pre to run the 2BLP pro I'm very hard pressed to hear any difference from the headphone out of either one……which is great when needing extra volume listening to vinyl or low output single ended sources…this 2BLP pro is here to stay. : )

My other blurb on the 2BLP pro. 2012
http://www.audiocircle.com/index.php?topic=106516.msg1095063

[servingko]

Glad you are enjoying it and it is in use.

[rob80b]

Even if I ever get around to modifying the K712s with a balanced cable for the BHA-1 the 2BLP will always find a useful place.

[rob80b]

And for those who like to look under the hood while I clean out any accumulated dust, although this one was fairly dust free considering its 13 years.

My previous 2BLP from 2001, Nippon capacitors.


And the current one from 2002, CDE USA capacitors.






Interestingly my previous two 3BSTs also had a similar change in capacitors

3BST 1999



3BST 2001

[R. Daneel]

Does the serial number signify Bryston made more than 200.000 amplifiers?

Also, does the 2B have two power transformers like the bigger amps?

Cheers!
Antun

[rob80b]

Does the serial number signify Bryston made more than 200.000 amplifiers?

Also, does the 2B have two power transformers like the bigger amps?

Cheers!
Antun

Good question..maybe...depends if they started at #1

Yes they're all mono design like their big brothers.

Current


2002


My original one I bought back in the early eighties looked like the one below with EI transformers prior to Bryston adopting the toroidals ...although the circuit design has remained almost unchanged.

198?



For the average user I still believe they are a great little amp; I had no problem powering my Dynaudio Special 25s at clean hefty volumes, maybe not as refined and resolute as my 4BSST but no slouch with surprisingly excellent deep and controlled base.

So how does this little 12 year old 60 watt 2BLP pro hold up these days running a pair of Dynaudio Special 25s with a nominal impedance of 4 ohms and a sensitivity of 88dB/2.83V/m, using the BCD-1 as a source and the BP25 as the pre with balanced Canare L-4E6S Star Quad balanced audio interconnects throughout, well there is more than enough power to get the Dyns cooking. I was surprised with the control it had over the 25s bass drivers the bottom end being very well defined, tight and deep.

[predrag]

2BLP PRO is the sweetest little amp I ever had in my hands.
With it`s superb build quality a true Bryston regardless of it`s maximium power output.
If you don`t listen at high volumes what more can you ask for?

[R. Daneel]

Hi Rob!

Thanks for the reply!

I can see you're using the Sennheiser HD700. How does it fare with BHA-1 and have you compared it to HD800?

Cheers!
Antun

[rob80b]

Hi Rob!

Thanks for the reply!

I can see you're using the Sennheiser HD700. How does it fare with BHA-1 and have you compared it to HD800?

Cheers!
Antun

Hi Antun

They pair very well together IMHO …I’m running them balanced and I’m very happy with the combo, clear and detailed with excellent layering and staging…. have not experienced the so-called treble peak many have mentioned…probably because of the BCD-1.

I did indeed try/buy the HD800s, great phones but not my choice to chill out with as I found myself gravitating more toward the 700s for long term listening enjoyment, the 800s were/are a bit more analytical …

My current go to and chill outs so far are still the Sennheiser HD700s, much prefer them over the HD800s for long term listening and overall musical enjoyment.

The HD700s are also the closest match I have found in a headphone to my Dynaudio Special 25s running off the 4BSST …so when I’m relegated to private listening it’s not too big a compromise.

[R. Daneel]

Hi Rob!

Excellent! Thank you!

So you find the HD700 more easy going than the HD800? That's interesting! How much does the HD700 benefit from balanced connection and which cable are you using? The Sennheiser cable perhaps?

Cheers!
Antun

[rob80b]

Hi Antun

I’m using the stock cable terminated with a Neutrik 4 pin XLR, is there a difference… hard to tell if also using a balanced source once levels are matched and IMHO I do not believe so as the BHA-1 either way is excellent to start with but I do appreciate the extra gain with balanced.
Nothing wrong with the HD800s but in direct comparison with the HD700s as I mentioned I found myself analyzing the recording more as opposed the to listening to the music, but that’s personal preference as my use of headphones is not really for critical listening, either way they are both excellent.
Seeing the thread started with using the 2BLP pro as a head amp I should mention that the Senns work much better off the BHA-1 as where the AKGs really shine with the increased current and wattage from the 2B and possibly a better impedance match.

[R. Daneel]

Hi Antun

I’m using the stock cable terminated with a Neutrik 4 pin XLR, is there a difference… hard to tell if also using a balanced source once levels are matched and IMHO I do not believe so as the BHA-1 either way is excellent to start with but I do appreciate the extra gain with balanced.
Nothing wrong with the HD800s but in direct comparison with the HD700s as I mentioned I found myself analyzing the recording more as opposed the to listening to the music, but that’s personal preference as my use of headphones is not really for critical listening, either way they are both excellent.
Seeing the thread started with using the 2BLP pro as a head amp I should mention that the Senns work much better off the BHA-1 as where the AKGs really shine with the increased current and wattage from the 2B and possibly a better impedance match.

Hi Rob!

Thanks for the reply!

Well, modifying the stock cable does make more sense since the original balanced cables by Sennheiser are rather expensive.

But I am really quite surprised the AKGs sound better on the 2B than they do on the BHA-1! This would mean they are even more demanding than the HD800s! I mean, I have a pair of K701s here (waiting to be shipped to a friend) and I own a pair of HD800s but I didn't notice K701s were lacking on the BHA-1. To me, the K701s seem like they need something really powerful and their specs don't really show it. Senn HD800 is demanding in a different way - it is just so articulate that the rest of the system has to deliver or you should have gotten something else in the first place. It's rather strange but what you are saying might really be the case and AKGs do in fact demand high current. Hmm...

[rob80b]

If I opted to do some surgery on the K712s (like the K702/Q701 they only a 3 pin mini XLR ) to accept a balanced cable..I’m sure they’d be fine with the BHA1, with my previous K701s as they had a four-conductor wire it was just a matter of adding the 4 pin XLR.



But yes ....something about those AKG drivers, more like driving speakers than headphones.

[R. Daneel]

Hi Rob!

Yes, this is very interesting! How did you connect the K701 to the 2N? With speaker banana connectors or bare wire perhaps? I know that some people used their K1000 with speaker amplifiers rather than headphone ones.

But I will have to try the HD700 and see if it is for me. From what you have told me and from what I have read it appears to offer some qualities of the HD800 but with the "fun factor" that can make it more enjoyable.

The question is, is it more fun than the Grado RS1 or PS500... That is something I have yet to establish.

[rob80b]

The 2BLP pro has more than enough output from its unbalanced headphone out to run any headphone even the K1000s as the headphone output is already wired to the speaker outputs but with resisters…. otherwise one could easily fry the drivers.
Many older receivers were also wired the same way for the headphone output, which is why many AKG users covet them; the nice thing about the 2BLP pro is that it’s a dual mono design with balanced inputs.
Now because of the resisters chosen there could be  an impedance mismatch with some makes of phones causing some odd tonal shifts and possible increased noise but the AKGs that I've used, DF240 studio monitors, K501s, K701s and now the K712s all seem to to quite happy with the Bryston especially with regards to the bass.
And as I mentioned earlier the HD700s do not benefit as much if at all, oddly though the efficient Grados also liked the 2BLP pro, probably for the current.

[R. Daneel]

I have had K240DF and K240M and used them with an OTL tube amplifier and they sounded great. The Monitor version was better IMHO with more midrange presence and just an overall more interesting sound. The DF version was flatter though and I used them with a Roland synthesizer to tune the sounds.

But I am very impressed with the 2BLP you have there! It actually has a headphone output which is really excellent.

I must tell you though, I'd be a little apprehensive at connecting the Grados to something so powerful. I have read that Grados need to be taken care of. On the other hand, the old AKGs were indestructible and could handle anything.

Okay, the HD700 will certainly be on my short list of headphones for 2015, thank you very much!

Best wishes,
Antun

[rob80b]

I have had K240DF and K240M and used them with an OTL tube amplifier and they sounded great. The Monitor version was better IMHO with more midrange presence and just an overall more interesting sound. The DF version was flatter though and I used them with a Roland synthesizer to tune the sounds.
........
Best wishes,
Antun

Fun stuff synths : ), I picked up my first 2BLP pro back in the 80s to power my Celestion monitors in the studio but soon discovered they brought the K240DFs to life.



Don’t worry about the Grados, much like the AKGs they run fine off a more powerful amp like the 2B.

Regards

Robert

[R. Daneel]

That's really aweome Robert!!

Thanks so much!

Your studio looks amazing! I can see an R2R machine in the background... This is a bit of an off-topic but I am really considering a Studer A80.

I am probably a little bit skeptical because some others have had problems with Grados. I am always very careful with my headphones - turning the amp off with volume at minimum setting when plugging and unplugging and always keeping them in a box, away from everything and everyone. I rarely listen to music at loud levels and even then it is rarely above 90 dB.

Since we're already talking about speaker amps with headphone outs wired to main output, is there anything else you know of that would work well with K701?

Because I have a feeling that with these kind of 'phones, the sheer output power players a greater role than amp's sophistication.

Cheers!
Antun

[rob80b]

That's really aweome Robert!!

Thanks so much!

...............is there anything else you know of that would work well with K701?

Because I have a feeling that with these kind of 'phones, the sheer output power players a greater role than amp's sophistication.

Cheers!
Antun

Hi Antun

If your listening levels are moderate I do not really see the need going for a more powerful amp, although it may help flesh out details at low volumes, much like many report when jumping to the bigger Bryton amps for their speakers
To bring up the bass on the AKG K700 series there is a reversible bass port mod which you may want to check out.
http://www.head-fi.org/t/660408/reversible-akg-k701-bass-mod

I found it worked really well on my K701s without changing it’s overall tonal characteristics.
http://www.head-fi.org/t/660408/reversible-akg-k701-bass-mod/105#post_10273369

Quote:
Originally Posted by Rob80b 
"Over the last few weeks I’ve been giving my K701s a lot more head time and interestingly enough I’ve found IMHO that those coveted aspects have greatly improved with the reinforced bottom end.
With the bass port mod there appears to be more pronounced layering, therefore a less two dimensional soundstage, more space and air if I may say so, treble extension and clarity remains the same but is now more evenhanded with regards to the overall aural spectrum and the fuller bottom end just makes my K701s more satisfying overall.
So by and large I guess I’m one of those “ppl” who have found the mod further improved rather than depreciate the K700 series signature, and yes it's more like adding a sub than increasing mid-bass."

Then you may want to pick-up a BHA-1, put a 4 pin XLR on the end of your K701s and then you’re done.

Interesting you’re considering an A80 in this day and age, muti-track or the 2 trk mastering?

[R. Daneel]

Hi Robert!

Thank you for links on K701 modification. It is most interesting!

I am considering the 2 channel version of A80. I really have no use for a multi-track version since I don't have a studio and while there were times I wanted to have one, I was never really interested in music production - I'm in a different field of engineering altogether - but I used to play in orchestra.

Is there anything you recommend when getting an R2R machine? Perhaps an A80 would be an overkill for me sp perhaps a B77 or PR99 would be more suitable. I am after a good cassette deck as well - have more than 300 metal and chrome tapes I would really like to use. They are hard to come by these days and virtually impossible to find if you want something that has not been tampered with.

I must say my fascination with Bryston digital equipment has always been in connection with their analogue-like quality to their sound. It is like analogue with resolution of the cutting edge digital equipment.

Cheers!
Antun