Jump to content
Why become a member? ×

Hartke LH1000 - one power amp not working


Berserker
 Share

Recommended Posts

Hi,

 

I just bought a used LH1000, and noticed the bridge doesn't work with the speakon cable. I checked output A with a 1/4" cable and it worked and sounded great, but there's no sound from output B, which I guess is why the bridge isn't working.

Any ideas what could be wrong? Do you think it could be user error somehow?

Link to comment
Share on other sites

Hmmm... tricky one this...

The LH1000 has two 500W power modules, like a stereo amp.

Page 12 of the manual says use a 'standard Speakon cable' - would this be two or four pin / conductors???

I'm guessing (!) that the 4 pin speakon out is wired as two 500W pairs, and in bridge mode you connect a single speaker between the 1+ and the 2+ as is usual with bridging stereo amps ?.

Not enough info in the manual.

LHseries_OM_EN_v2.pdf (samsontech.com)

 

Link to comment
Share on other sites

It could be that an input ribbon cable / connector inside has worked loose which has happened to me in the past (on the right hand power amp module).

Edited by Dood
Link to comment
Share on other sites

1 minute ago, Dood said:

If in stereo / dual mode, (with the balance set to middle) nothing comes out of one of the outputs, then there’s a fault somewhere.

Yeah, that's what I thought 😣

 

5 minutes ago, Dood said:

It could be that an input ribbon cable / connector inside has worked loose which has happened to me in the past (on the right hand power amp module).

Thanks, I'll open it up and see if I can find anything obviously loose.

 

26 minutes ago, Bigguy2017 said:

Hmmm... tricky one this...

The LH1000 has two 500W power modules, like a stereo amp.

Page 12 of the manual says use a 'standard Speakon cable' - would this be two or four pin / conductors???

I'm guessing (!) that the 4 pin speakon out is wired as two 500W pairs, and in bridge mode you connect a single speaker between the 1+ and the 2+ as is usual with bridging stereo amps ?.

Not enough info in the manual.

LHseries_OM_EN_v2.pdf (samsontech.com)

 

From the research I've done it's just a standard speakon.

  • Like 1
Link to comment
Share on other sites

18 minutes ago, Dood said:

Good luck, hopefully something simple! IIRC it’s a pretty repairable amp too.

Good to know... took the top off and can't see anything obvious. Guess I need to look for a local amp repair shop.

Link to comment
Share on other sites

Basic question that might seem stupid : Did you put the switch to the bridge position ?

And yes, it's a standard Speakon speaker cable.

I had one for a day and send it back as I could not stand those hugely noisy fans, it was like having a wind turbine nearby !

Link to comment
Share on other sites

4 minutes ago, Hellzero said:

Basic question that might seem stupid : Did you put the switch to the bridge position ?

And yes, it's a standard Speakon speaker cable.

I had one for a day and send it back as I could not stand those hugely noisy fans, it was like having a wind turbine nearby !

Yes, it was in bridge mode when I used the speakon. I then changed it to unbridged mode to try the 1/4" lead and Output A worked fine... nothing from Output B.

Strange, the fans aren't that noisy at all on this one. You certainly wouldn't notice it on a stage.

Link to comment
Share on other sites

On stage at loud level, yes.

In a studio environment at low to normal level, it's just impossible to use as it's way too noisy, but, that said, it's a really simple and good sounding amp, for sure.

Can't you hear the massive air flow ?

That said, it's a major problem with almost all fan cooled amps, except the AER and Glockenklang amps, which have dead quiet fan air cooling.

Link to comment
Share on other sites

6 minutes ago, Hellzero said:

Can't you hear the massive air flow ?

No more than any other amp I've owned, can't say it would bother me when recording. The fans are definitely going but I've heard louder for sure.

Link to comment
Share on other sites

1 hour ago, Berserker said:

Yes, it was in bridge mode when I used the speakon. I then changed it to unbridged mode to try the 1/4" lead and Output A worked fine... nothing from Output B.

Strange, the fans aren't that noisy at all on this one. You certainly wouldn't notice it on a stage.

Sounds like output B is dead - so bridge mode isn't going to work. 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...