One thought on “PS Audio BHK Signature 250 Stereo Power Amplifier”
The carton arrived on a Tuesday, and FedEx driver set it down with the particular sigh of someone who has just handled 83 pounds of American iron. Inside, nested in its own little coffin, was a small box of tubes. Two of them. Gold Lion 6922s, hand-matched, which PS Audio ships separately so that UPS can’t have its usual fun with them. I installed them through the top hatch, felt briefly like a mechanic in 1962, and switched the thing on.
The idea behind it. Bascom H. King has been building hybrid amplifiers since Carter was president and my hair was a different color, and the BHK 250 is the last and most fully realized expression of that lineage. The concept is simple to state and fiendish to execute: let a tube do the delicate work of receiving and amplifying the small signal, then hand the heavy lifting to silicon that doesn’t care how loud you play Zeppelin.
So the input stage is a balanced differential pair of 6922s, running in class A off their own isolated, regulated supply — the tubes never share a power rail with the output devices, which is a bigger deal than it sounds. Anyone who has heard a hybrid go grainy at volume has heard what happens when the output stage’s current demands come rummaging through the front end’s supply looking for spare change.
The output stage is where King got interesting. Nearly every solid-state amplifier you’ve owned uses complementary output devices — N-channel handling the positive half of the waveform, P-channel the negative — and the dirty secret is that P-channel and N-channel devices are cousins, not twins. They don’t behave identically, and the asymmetry shows up as distortion right where your ear is most sensitive to it. King’s answer was to say the hell with it and use only N-channel MOSFETs for both halves of the waveform. Same device type, same transfer characteristics, same behavior top and bottom, and a waveform that comes out very nearly symmetrical.
There’s no free lunch, and King has never pretended otherwise. Driving an N-channel device on the negative swing requires circuit gymnastics — level shifting, a floating drive arrangement — and the topology leans on a meaningful amount of global feedback to keep everything linear. It also skews the residual harmonic structure toward odd orders rather than the euphonic even-order stuff that makes bad tube amps sound “warm” to people who like that sort of thing. I mention this because it’s precisely the sort of detail that sends internet forums into a two-hundred-post spiral, and because in my listening room the argument evaporated within about four bars.
Build quality is the old religion: through-hole construction, no surface-mount, hand-soldered PRP resistors and film-and-foil capacitors, separate transformers and supplies for the tube and solid-state sections. You can see the wiring. You can also, if you’re the type, roll the tubes in about ninety seconds without a screwdriver, which is either a feature or the beginning of an expensive personal problem. I speak from experience.
The numbers, briefly:
250Wpc into 8 ohms, 500Wpc into 4, and stable into 2 for musical transients
Gain 30.5dB; 1.3V in for full output; balanced XLR (true balanced) and single-ended RCA
Input impedance 200k balanced / 100k unbalanced — it will not bully your tube preamp
THD+IM under 0.01% at 1kHz; frequency response 10Hz–20kHz ±0.1dB, out to 200kHz at -3dB
Output impedance under 0.1 ohm, damping factor 100
83 lbs, 17.1″ wide, and it runs warm enough to be a cat magnet
$8,499 when new; discontinued from production in 2025, which has made the factory-certified units something close to larceny
Numbers, as always, tell you what the amplifier won’t do wrong. They tell you nothing about what it does right.
What it does right. Give it an hour. Cold, it’s competent and slightly flat-footed; warm, it opens like a hand unclenching. The first thing you notice — and this is the tube stage talking — is that images have mass. Not size, mass. A tenor saxophone on a good pressing of a Contemporary date doesn’t hover in space as a tidy hologram; it occupies a volume of air, with a reed and a brass body and a room behind it. The BHK gives you the whole object.
The second thing is the silence. Absolute black between notes, no tube rush, no transformer hum leaking into quiet passages. On solo piano the decay tails go down and down until they simply stop being audible, without that little floor of hash where lesser amplifiers give up.
Bass is deep, tuneful and beautifully articulated — you hear pitch and fingering, not just thump. If I’m being honest, the very bottom octave has a hair less iron-fisted slam than the best big class-A monoblocks I’ve had in the system. It’s a matter of degree, not of kind, and a serious power cord and a clean AC feed close most of the gap.
Treble is airy and extended without a trace of etch, and dynamics — micro and macro both — are startling. Full orchestra at a realistic level, and the amp never once sounded like it was working. Rock is where hybrids traditionally embarrass themselves and where this one grins.
And yes, the tubes. Swap the stock Gold Lions for a good vintage pair and you get a touch more sweetness and air. Then you buy another pair. Then it’s 2 a.m. and you’re bidding on German glass. Don’t say I didn’t warn you.
Final verdict. The BHK Signature 250 is that rare hybrid that isn’t a compromise between two philosophies but a genuine synthesis of them — the tube’s humanity and the transistor’s authority, in one 83-pound box, with a topology unusual enough to be interesting and executed well enough to be right. It won’t out-slam a pair of massive class-A monoblocks in the bottom octave, and it wants an hour and clean power to give you everything. Feed it those and you get bloom, silence, dimensionality and 250 unbothered watts, from a company that will still answer the phone.
At original retail it was a bargain. At what these go for now, it’s arguably the best hybrid amplifier per dollar anyone has built. Very highly recommended.
The carton arrived on a Tuesday, and FedEx driver set it down with the particular sigh of someone who has just handled 83 pounds of American iron. Inside, nested in its own little coffin, was a small box of tubes. Two of them. Gold Lion 6922s, hand-matched, which PS Audio ships separately so that UPS can’t have its usual fun with them. I installed them through the top hatch, felt briefly like a mechanic in 1962, and switched the thing on.
The idea behind it. Bascom H. King has been building hybrid amplifiers since Carter was president and my hair was a different color, and the BHK 250 is the last and most fully realized expression of that lineage. The concept is simple to state and fiendish to execute: let a tube do the delicate work of receiving and amplifying the small signal, then hand the heavy lifting to silicon that doesn’t care how loud you play Zeppelin.
So the input stage is a balanced differential pair of 6922s, running in class A off their own isolated, regulated supply — the tubes never share a power rail with the output devices, which is a bigger deal than it sounds. Anyone who has heard a hybrid go grainy at volume has heard what happens when the output stage’s current demands come rummaging through the front end’s supply looking for spare change.
The output stage is where King got interesting. Nearly every solid-state amplifier you’ve owned uses complementary output devices — N-channel handling the positive half of the waveform, P-channel the negative — and the dirty secret is that P-channel and N-channel devices are cousins, not twins. They don’t behave identically, and the asymmetry shows up as distortion right where your ear is most sensitive to it. King’s answer was to say the hell with it and use only N-channel MOSFETs for both halves of the waveform. Same device type, same transfer characteristics, same behavior top and bottom, and a waveform that comes out very nearly symmetrical.
There’s no free lunch, and King has never pretended otherwise. Driving an N-channel device on the negative swing requires circuit gymnastics — level shifting, a floating drive arrangement — and the topology leans on a meaningful amount of global feedback to keep everything linear. It also skews the residual harmonic structure toward odd orders rather than the euphonic even-order stuff that makes bad tube amps sound “warm” to people who like that sort of thing. I mention this because it’s precisely the sort of detail that sends internet forums into a two-hundred-post spiral, and because in my listening room the argument evaporated within about four bars.
Build quality is the old religion: through-hole construction, no surface-mount, hand-soldered PRP resistors and film-and-foil capacitors, separate transformers and supplies for the tube and solid-state sections. You can see the wiring. You can also, if you’re the type, roll the tubes in about ninety seconds without a screwdriver, which is either a feature or the beginning of an expensive personal problem. I speak from experience.
The numbers, briefly:
Numbers, as always, tell you what the amplifier won’t do wrong. They tell you nothing about what it does right.
What it does right. Give it an hour. Cold, it’s competent and slightly flat-footed; warm, it opens like a hand unclenching. The first thing you notice — and this is the tube stage talking — is that images have mass. Not size, mass. A tenor saxophone on a good pressing of a Contemporary date doesn’t hover in space as a tidy hologram; it occupies a volume of air, with a reed and a brass body and a room behind it. The BHK gives you the whole object.
The second thing is the silence. Absolute black between notes, no tube rush, no transformer hum leaking into quiet passages. On solo piano the decay tails go down and down until they simply stop being audible, without that little floor of hash where lesser amplifiers give up.
Bass is deep, tuneful and beautifully articulated — you hear pitch and fingering, not just thump. If I’m being honest, the very bottom octave has a hair less iron-fisted slam than the best big class-A monoblocks I’ve had in the system. It’s a matter of degree, not of kind, and a serious power cord and a clean AC feed close most of the gap.
Treble is airy and extended without a trace of etch, and dynamics — micro and macro both — are startling. Full orchestra at a realistic level, and the amp never once sounded like it was working. Rock is where hybrids traditionally embarrass themselves and where this one grins.
And yes, the tubes. Swap the stock Gold Lions for a good vintage pair and you get a touch more sweetness and air. Then you buy another pair. Then it’s 2 a.m. and you’re bidding on German glass. Don’t say I didn’t warn you.
Final verdict. The BHK Signature 250 is that rare hybrid that isn’t a compromise between two philosophies but a genuine synthesis of them — the tube’s humanity and the transistor’s authority, in one 83-pound box, with a topology unusual enough to be interesting and executed well enough to be right. It won’t out-slam a pair of massive class-A monoblocks in the bottom octave, and it wants an hour and clean power to give you everything. Feed it those and you get bloom, silence, dimensionality and 250 unbothered watts, from a company that will still answer the phone.
At original retail it was a bargain. At what these go for now, it’s arguably the best hybrid amplifier per dollar anyone has built. Very highly recommended.