Border Patrol 300B SE driving ability

opusover21

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Must admit I can never get comfortable with the answer to this but I would like to dabble valves at some point….

Something like the 8watt monsters like Border Patrol products…just how what kind of speaker can you hook them up to…???? My Audio Physics Virgo III’s are claimed 90db 4 ohm load…3 way speaker…I get a different answers to will such a design work with the Audio Physics speakers…

Yet on the BP site it makes claims “….but the amplifier is equally comfortable driving more real world designs, though the recommended efficiency for partnering loudspeakers to extract the maximum performance needs to be greater than 90dB/watt. One reviewer was staggered to find the SE300B driving a loudspeaker that had defeated everything but his 400W channel transistor amplifierâ€

So as an example would the BP work with the Virgo’s? or any other reasonable load speaker or should I (as I am increasingly thinking) consider amp/speakers as a package which have a magical synergy? regardless of the paper specs?

 

Hawk

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For best results I do think you have to look at the amp/speaker package as a whole... and in the context of the room and volume levels you wish to obtain.

What I can say is that Border Patrol products can be made to sound outstanding with more grunt that you would imagine possbile from 300bs

 

auralflea

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You should discuss this with PAG - he has a pair of Audio Physics driven by a Tube Tech Unisis Signature valvie. Admittedly at 30W/ch that is a bit more potent than the BP at 8W, but I assure you it is plenty enough for most of us...

Kevin

 

Hawk

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Aural Flea wrote:

You should discuss this with PAG - he has a pair of Audio Physics driven by a Tube Tech Unisis Signature valvie. Admittedly at 30W/ch that is a bit more potent than the BP at 8W, but I assure you it is plenty enough for most of us...Kevin
Good call... The only thing I would say is that one of the strengths of Border Patrols are the power supplies. It seems to allow the amp to deliver more current than average. Murray or I should coco can probably explain this better than I can. All I can say with confidence is that my S20 has bucket loads more drive and bass extention than my previous and more powerful prima luna. That said 8 Watts still has its limitations...

 
M

murray johnson

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I think your amp will be more like 18-20W Hawk.

The twin power supplies and the interstage driver transformers do help it to deliver some oomph at the bottom too. Many SE's will give up quite early on into a tricky load whose impedance dips too much.

 

jonjin

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I think your speakers will absolutely sing with valves driving them. I don't think absolute numbers are useful. It depends on the size of your room, the type of music you listen to and how loud.

That said, the BP amps are special with their power supply constantly providing a stable power source whether playing music loud or soft. At Hawk's bakeoff we were only listening at the 9 o'clock position and it was definitely loud!

JJ

 

Hawk

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murray johnson wrote:

I think your amp will be more like 18-20W Hawk.The twin power supplies and the interstage driver transformers do help it to deliver some oomph at the bottom too. Many SE's will give up quite early on into a tricky load whose impedance dips too much.
18-20W is spot on for the S20 although since Kevin's last tweak Im pushing the valves a bit harder in mine so probably have another couple of watts in hand. I meant the 8W the SE has..

Also the SE might only have one power supply? Not sure if thats relavent though given it has half the Valve count

 

PAG

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SE amps sound more powerful than push pull ime (same wattage output comparing like for like), and i recently tried a 12w ultralinear pp valve amp...at 9o`clock it was too loud for me! (enough control of the bass drivers too!)

The only problem you may experience is in the bass (which could be said of most valves compared to ss muscle) but then again with the BP, you may not.

Only way to tell is to try it, but i think it will be ok
smile.png


 

i_should_coco

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Valve amps tend to overload much more gracefully so appear more powerful than their ratings would suggest. Remember also, that doubling the power only gives you an extra 3dB of volume - the difference is barely audible.

Having said that, there is a limit - people often say that valve amps sound soft and dull or don't have dynamics and this is usually a symptom of a less than optimum match.

Low impedances aren't a great idea, but often amps have 4 Ohms taps (not sure about the BP - Neil?). Really difficult loads are best avoided.

The Audio Physics seem to be a bit of a borderline case, they could work well, but the only way to know for sure is to try.

Cheers,

Pete

 

Hawk

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i_should_coco wrote:

Valve amps tend to overload much more gracefully so appear more powerful than their ratings would suggest. Remember also, that doubling the power only gives you an extra 3dB of volume - the difference is barely audible.Having said that, there is a limit - people often say that valve amps sound soft and dull or don't have dynamics and this is usually a symptom of a less than optimum match.

Low impedances aren't a great idea, but often amps have 4 Ohms taps (not sure about the BP - Neil?). Really difficult loads are best avoided.

The Audio Physics seem to be a bit of a borderline case, they could work well, but the only way to know for sure is to try.

Cheers,

Pete
The S20 does have a 4 Ohm tap, but Im not sure about the 300 SE

 

PAG

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The Audio Physics tend not to wander too mutch in their impedance, giving a relativly near 6 ohm load.

I have found they sound their bst on an 8ohm tap on the amp, they seem more open and controlled with that setting.

 

Dik Dolan

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I just had a quick look on the steophile site, and in the test of your speakers they say

"The Audio Physic Virgo III is of above-average voltage sensitivity, my estimate coming in at 89.2dB(B)/2.83V/m, which is in reach of the specified 90dB. However, its impedance plot of magnitude and electrical phase against frequency (fig.1) reveals it to be a moderately demanding load. Not only does the speaker feature a minimum impedance of 3.5 ohms at 572Hz, but the combination of 5.5 ohms and -42 degrees at 78Hz will stress low-powered amps if the user wants to rock out on bass-heavy music."

http://www.stereophile.com/floorloudspeakers/919/index5.html

So I guess it all depends.... if you want thundering volume levels in a large room playing demanding complex music then 300b SETs wouldnt be my first choice, with your speakers. On the other hand, if you play at what I'd call "normal" volumes then I'd say it could work..but definately try to arrange a home demo.

I use a Glasshouse 300b SET amp into IPL S3 speakers that are an easy impedance load, and around 89db and have no problems with lack of grip or power, playing everything from Led Zep to Beethoven, but I only listen at low to moderate volumes, in a small room.

 

opusover21

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Guys really useful comments there...thanks DD ta very much...I play at low volumes and lower than most or average...a typical "classic" cd that would represent the type of music would be Ray Lamontage, Damien Rice etc...

I'm not adversed to having to change the speakers but I's sure certain combinations will work better than others such as the obvious living voice...but do want to be happy in the meantime!

Top work guys..!

 
M

murray johnson

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Despite your listening habits, I'm not convinced this particular combination of amp and speakers will be as successful as you'd hope. Do try to get a BP at home for a few days before committing. They are very fine amps but, as the sports commentators say, "It's a big ask"

 

Markus

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opusover21 wrote:

So as an example would the BP work with the Virgo’s? or any other reasonable load speaker or should I (as I am increasingly thinking) consider amp/speakers as a package which have a magical synergy? regardless of the paper specs?
I can speak from experience here, having tried a number of different amplifiers on a Virgo III which I had at home for more than a year. A SE300B is definitely not a good match for the Virgo III. They need a bit more power than a single 300B per channel can provide (haven't tried a parallel single ended amp).

The Virgo III also likes to see a reasonably low output impedance on the amp.

One combo that was a lot of fun was a Nait 2.

 

Tune

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Again, it makes little sense to run a SE amp like the BP at or near it's limits with unsuitable speakers - these amps like to idle and pushing them will only result in increased distortion and lowered headroom. The SE would even harden up when used with Avatars.

 

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