Owner's Manual

Owner’s Reference BHK Signature Ampliers

4826 Sterling Drive, Boulder, CO 80301 Introduction

PH: 720.406.8946 support@psaudio.com www.psaudio.com 15-070-01-1

Rev B

Introduction

Thank you for your purchase of the PS Audio

BHK Signature Amplier.

ampliers represents one man’s decades long pursuit of perfection. Nothing was spared, no

shortcuts were taken.

Power ampliers are the make-or-break component in a music reproduction chain. Everything

in your system funnels into this critical component and anything lost can never be recovered. To

solve this problem, the BHK Signature was designed as a hybrid amplier featuring a zero-loss

vacuum tube input stage coupled to a high bias dierentially balanced MOSFET output.

There are two dedicated models in the Signature Series, the 250 stereo and the 300 monoblock.

Each model is housed in the same chassis with the identical circuit components; the stereo has

two channels, the mono one. In the stereo 250 one input tube is used for each of the two channels,

in the mono 300 both tubes are used in parallel to lower noise and double current. The same

methodology of parallel connection is employed in the MOSFET output stage as well.

Output speaker connectors are custom machined out of copper, then gold plated. There are two

pair per channel on the stereo 250, and two pair on the mono 300. Each of the connectors was

engineered specically to benet the performance qualities of the BHK Signature.

The unit is shipped with a pair of hand matched Gold Lion 6922 vacuum tubes, installed in their

proper sockets and ready for use. If you wish to experiment with dierent tubes, you may use most

6 or 7 Series triode without changing the bias, which is adjusted automatically. Tube rolling, as it

is known, is common practice and an entirely dierent sound quality can be achieved by changing

tube types.

There are 6 fuses on the BHK Signature. 4 of the fuses are for the high voltage power supply rails.

The remaining two are AC input fuses, one each for the two power transformers. The smaller

AC input fuse passes power to the separate vacuum tube power supply, the larger fuse for the

massive power output stage transformer. It is possible to replace the supplied fuses with high-end

versions, but we recommend care be taken to use H-Rated fuses, specically tailored for high

current, high transient in-rush conditions.

Power cords matter. We recommend using a high-end power cord to replace the courtesy stock

power cord supplied with the BHK Signature.

Break in matters. The BHK Signature should sound quite good out of the box, but far better

with a hundred or so hours of on-time. It is not necessary during the on-time to play music.

Simply leaving the amplier in the ready position will help the MOSFET power section improve its

performance over time. The tubes also need break in, but that time should be limited to 24 hours

of constant on-time to preserve their life.

Thank You

Zero Loss

Connectors

Break In

Two Models

Vacuum Tubes

Fuses

Power Cords