How To Tell If You Have The Latest Version Of BHK Signature 250, 300 or Preamp???

I know there seems to be a lot of new and used models of BHK for sale on various sites!

How does one know if they are getting latest versions and is there a update program for earlier units.

Thanks In Advance

Unless they were the betas the BHK have never changed and there is no update.

How do you know if you are have or buying a beta unit?

Welcome, Mr. Jem!

I’m unclear regarding Paul’s response. My BHK 250 went back to Boulder after a major failure. While being repaired, there were several updates completed on the unit with the serial number changing to reflect the revisions. I don’t remember exactly how the serial number worked but one of the last digits was changed to an 8 to reflect revision 8. One of the changes had to do with internal grounding. My BHK 250 was not, to my knowledge, a beta unit. I bought it from an authorized internet dealer and the unit was drop shipped directly from PS Audio.

One final note, none of the revisions had any impact on the performance of my amp. The repair, of-course, did.

I have a beta BHK 250 and it was updated a while back, though the only thing I know for sure was changed are the binding posts. The original binding posts had a bad habit of stripping the threads, not good for making solid connections to your speaker cables! While this is not definitive, the early binding posts had a hexagonal head, perfect for applying too much torque. The new binding posts are round and knurled, perfect for struggling to get them too tight. I’m pretty sure this change was made either before regular production began or shortly thereafter. With respect to the BHK 300, I not sure if early units used the hexagonal binding posts, but if they are there it’s an early build unit.

I can’t speak to the BHK Pre since mine is a recent build and I don’t recall any discussion of changes in the lead up to my getting it.

amsco15 said

I’m unclear regarding Paul’s response. My BHK 250 went back to Boulder after a major failure. While being repaired, there were several updates completed on the unit with the serial number changing to reflect the revisions. I don’t remember exactly how the serial number worked but one of the last digits was changed to an 8 to reflect revision 8. One of the changes had to do with internal grounding. My BHK 250 was not, to my knowledge, a beta unit. I bought it from an authorized internet dealer and the unit was drop shipped directly from PS Audio.

One final note, none of the revisions had any impact on the performance of my amp. The repair, of-course, did.

Amsco

Equally puzzled on Paul’s response. My BHK 250 came back from Boulder a couple of weeks ago after a major failure in the fault mode that made the unit inoperable. While the serial number remained the same after its trip, the unit (which while among the first production units was not a beta unit) was designated as a ‘revision 2’ and underwent eight updates during its repair according to the ever helpful James to revision 8. Two of these were major - one to do with a modification to improve the bass response and a second related to fuse blowing issues which is where my fault mode problem originated. The other 6 were evidently minor and not described. Regarding the revisions, I am still burning in a new set of GL 6922s so can’t comment on the performance other than the unit is working and sounds better and better each day.

Mike

Doh. Old age is my excuse. Sorry. I had forgotten about the protection upgrade. There was a problem with some earlier units that didn’t protect from DC problems should they arise. It didn’t impact the performance at all and was more of a ‘just in case’ sort of update. I am not sure what serial numbers qualify. The easiest way to find out is to give us a call. Sorry for the misinformation.