Details are ready to go


#1

Ok, the full story, videos, specs and details on the BHK Signature 250 and 300 power amplifiers has been posted. http://www.psaudio.com/products/bhk-signature-amplifier/

Hopefully we covered everything. have fun.


#2

Why does it say the following?

“In stock, available for shipment”


#3

Probably because I screwed up. Thanks for catching it.


#4
Paul McGowan said Probably because I screwed up. Thanks for catching it.
LOL! I really have a deep appreciation for a CEO with such openness!!!41_gif

#5

Thanks Woot. I hardly would like to admit the number of times that happens!!

Looks like a bug in the program. It says available, but it is backorder only. I have a programmer set to tackle it Monday.


#6

Excitement on your part is my guess for the stock error, Paul!

Please note the product description states the following; “The BHK Signature power amplifier culminates one man’s lifelong quest for perfection in power amplification. Bascom H. King’s magnum opus combines a vacuum tube input with a powerful MOSFET output capable of either 250/400 watts per channel in the Stereo 250”. The Specsification Page states minimum 250 WPC into 8 ohms and 500 WPC into 4 ohms. The disparity will cause confusion.


#7

The details say:

  • 250 watts per channel 8Ω Signature 250 stereo
  • 500 watts per channel 4Ω Signature 250 stereo
  • 2Ω stable Signature 250 stereo <-- What about the wattage?
  • 300 watts 8Ω Signature 300 mono
  • 500 watts 4Ω Signature 300 mono <-- 500 or 600? http://www.psaudio.com/bhk-signature-250300-amplifiers/ says 600
  • 1000 watts 2Ω Signature 300 mono
What does "2Ω Stable for musical transients" actually mean? How stable? What about non-transients? Will it be stable at 1Ω? 0.5Ω? Was the amp tested on such loads? If there were specified wattage, no such questions would have arisen.

#8
nortonkp said Excitement on your part is my guess for the stock error, Paul!

Please note the product description states the following; “The BHK Signature power amplifier culminates one man’s lifelong quest for perfection in power amplification. Bascom H. King’s magnum opus combines a vacuum tube input with a powerful MOSFET output capable of either 250/400 watts per channel in the Stereo 250”. The Specsification Page states minimum 250 WPC into 8 ohms and 500 WPC into 4 ohms. The disparity will cause confusion.

Yes, thanks. I'll correct it. What would I do without you guys?

#9
Alekz said The details say:

What does “2Ω Stable for musical transients” actually mean? How stable? What about non-transients? Will it be stable at 1Ω? 0.5Ω? Was the amp tested on such loads? If there were specified wattage, no such questions would have arisen.


That’s a good question and not sure how else to put it. Open for suggestions. We were hesitant to rate it at 2Ω because we don’t want people to think it should be used to drive 2Ω loudspeakers (are there any 2Ω loudspeakers?). It will do fine with speakers that dip to 2Ω and for that matter, even 1Ω (and yes we’ve tested it). Hence the wording.

The monoblock version can actually put out enough to handle a 2Ω loudspeaker with dips to 1Ω or even 0.5Ω but only transients as one would expect,


#10

Paul, what do you mean to communicate by “stable?”

“2Ω Stable for musical transients” implies the amp will be less than stable at lower impedance and perhaps oscillate or something else. It also implies if the load at 2Ω is longer than a transient, the amp will be unhappy.

As I read the spec, I get the impression the amp has limitations other amps do not, when I expect you are meaning to communicate it has more capability than most.


#11

Correct Elk, that is what I wish to convey. It is not less stable or held back, rather, it will handle these dips and bumps just great. You’re a better wordsmith than I. Suggestions?


#12

Some loudspeaker loads are especially difficult to drive. Loudspeakers are reactive loads, not just resistive; they have inductance and capacitance. The BHK Signature 250 and 300 power amplifiers are insensitive to (easily handles/manage) difficult loads and capable of continuous operation into a 2 ohm load.

I think something like “capable of continuous operation into a 2 ohm load” “easily handles difficult loudspeaker loads with low impedance dips” is what we as end users need to understand.

Perhaps this will operate as a springboard for others.


#13
Paul McGowan said we don't want people to think it should be used to drive 2Ω loudspeakers (are there any 2Ω loudspeakers?).
Yes, some Apogees are 1Ohm nominal, Martin Logan speakers go down to 0.5Ohm. Hence my concerns about the BHK250 ability to drive them. The damping factor (100) is also not high in comparison to, say, Pass Labs x250 series (250@8Ohm). BTW, is the stated dumping factor measured @4 or @8Ohm?

BHK stepping in here - I am seeing an obsession with low impedance driving ability of the BHK Signature amps. The amp is not an arc welder but a musical sounding amp which will drive most speakers well. In the event that one excessively drives a difficult load, the protection circuit will shut the amp down and/or blow some of the output stage rail ruses. That will tell what it will do under those circumstances. I believe the experience of the beta testers will be very useful in finding out how the amp fares with a variety of loads.


#14
Alekz said Yes, some Apogees have 1Ojm nominal . . .
10jm? 1Ω? Which Apogees are 1Ω nominal?

As to Paul’s question, I am unaware of any 2Ω nominal speakers. Some dip below 2Ω for some frequencies.


#15

Based on the specs, Paul’s comments and BHK’s comments, the BHK 250 Signature Stereo amp is designed to drive speakers which present as low as a 4 ohm nominal load to an amp and which have as low as 2 ohm peaks within their frequency response range. Based on the specs, the BHK 300 Signature Monoblocks are designed to drive speakers which present as low as a 2 ohm nominal load to an amplifier. Those with exotic electrostats appear to require the latter amps.


#16

Why no pictures of the internals for each page describing the tube and MOSFETs? Or the power supply?

Juuuuuuust sayin’.

–SSW


#17
BHK stepping in here - I am seeing an obsession with low impedance driving ability of the BHK Signature amps. The amp is not an arc welder but a musical sounding amp which will drive most speakers well.
Thank you, Bascom. Wonderful real-world approach and a perfect choice - sound over specs and audiophile drama.

#18

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#19
Elk said
Alekz said Yes, some Apogees are 1Ohm nominal . . .
10jm? 1Ω? Which Apogees are 1Ω nominal?

As to Paul’s question, I am unaware of any 2Ω nominal speakers. Some dip below 2Ω for some frequencies.

Apogee Scintilla, for example. http://www.apogeespeakers.com/scintilla.htm

Electrostats (and ribbons) are capacitive, so their impedance curves tend to go down if the frequency increases.


#20

It looks like they will pair nicely with my VSA 5 SE’s!devil_gif