Using 2 separate speaker cabinets with the H&K GM 36 single speaker out port

Not sure if anyone on this forum knows about this;

Before purchasing this amp I was always used to amps that had 2 speaker outputs in the rear so you can have 2 cabinets regardless of speaker configurations, 1x12", 2x12', or 4x12". So when I decided I wanted it and not wanting to trade my EVH 5150 III white & Blackstar HT Venue cabinets, both with Celestions in for a single 2x12" or one with a parallel output thru to the other (I like my little black & white amp "stack"), I looked around online and spoke with sound experts at various musical instrument stores and they all recommended the Palmer PCABM box cabinet merger. Its a tiny little all metal device with outputs for 2 cabinets and 2 inputs to choose from Serial or Parallel (only 1 can be used) depending on which will result in the total impedance of Ohms at the cabinets. So I found and ordered one on ebay, they are less that $50, and yes it does what it claims. I find using my 2 cabinets on this amp makes the tone warmer, more full, and even clearer. For those of you that would like to have the same setup do a google search for Palmer PCABM Cabinet Merger, check it out...

I believe Bordonburt answered this query in another post right above this one (or wherever it`s proximity may be once you get to reading this LOL).

There are a handful of solutions for you, and the box you purchased is but one of them. If you are using the series circuit it would explain the experience of hearing a warmer amp (or it could be a total placebo. Either way you`re finding your amp more pleasant) by giving it more of a resistance to work against.

Me, I`m one to crack out the soldering iron at the slightest sign of saving substantial money. In setting up my two GM36 rig and getting it as clean as possible (wiring wise), I needed six right angle cables. I had two, the rest were straight plugs. The cables I wanted were $35 each, so $140 out of pocket. Yeah...NO. Spent $20 on some solid right angle connectors and about 20 minutes of time and turned my straight ends into gold plated right angles. $120 saved. (conversely I did purchase a device for this rig that I tried to make a cable for that didn`t do what I wanted it to. It didn`t sound good. That will be covered in my thread regarding this particular setup)

Thanks Jeff, we're getting into the realms of thread duplication here. Jeff's right, I gave an in detail response to this post in the thread "GM36 with 2 cabs?" and this starter post is a direct Cut and Paste of the one I responded to. Nothing wrong with that but it would have been better to get in touch with a Moderator and ask for it to be shifted into its own thread. It's better for server storage space and for managing responses in the one place.

For the benefit of other members coming across this, I think it should be noted that this device certainly works but is vastly overpriced at £35 / $50! It is just a small box with 4 jack sockets, (two need to be switching jacks), and a foot of hookup wire in it, nothing more!!! .

I posted a wiring diagram for hooking up one of your own in the other thread: GM36 with 2 cabs While there is nothing at all wrong with the Palmer device, at that price it's a "choose to pay through the nose for convenience" decision, you could easily make your own with an hour or so work for a lot less.

It is also no better than making a custom parallel or series cable with 3 plugs and a few feet of speaker wire.

Here are my original replies.  You may disagree with me of course but just to add back in the other side of this to keep the thread up to date and balanced:


1)

Oh dear, sorry to be the bearer of bad news but I wish you had got back in touch with us before you bought that.  It's nothing more than a little tin box with 4 jack sockets and a few inches of hookup wire setup according to a very simple wiring diagram inside!  And they charged you best part of $50 for that?  I'm going into production, there's gold in them thar hills!  

The problem is that you described them as "sound experts at various musical instrument stores".  I know it is natural to see them as that but they are usually anything but sound experts, they have a very different job to do and it relies on different knowledge.  You are putting too much faith in people who are for the most part salesmen and occasional techs.  Remember, they are employed there solely to help the store make its money by selling you equipment and their advice cannot be guaranteed to be impartial.  Sure they may know their range of gear, or they may know what problems commonly occur with what models of gear and how to fix them, but at the end of the day they want to put money into their till and there is a plethora of musical gear out there which is designed to do that at very low cost to them.  When was the last time you came across a salesman recommending something that he doesn't stock and can't get, as better for your purposes than the range he does stock, effectively sending you somewhere else to buy something?

Never mind, spilt milk and all that and it won't break the bank, but it really is best to take the advice you get on this sort of stuff from those "sound experts" with a pinch of salt until you have it confirmed by someone independent who doesn't stand to gain from your buying the shiny googaw.  And it has to be said, I take an old fashion view that your $40 over the top is better in your pocket than theirs while today's view is usually that, "it's only 50 bucks so what the heck!"  $50 is $50 but it could be said it's me that's out of step.

Incidentally, I have two of the cables below.  One is wired for series and the other for parallel, 6 solder joints each.  Total cost for the two with good quality oversize plugs specifically made for speakers, less than $10.  Additional contacts added, none.



There's nothing exotic about it.  The bottom plug is to the amp, the middle plug is to the top 1x12" and the top plug is for the bottom 1x12".  The top two are just wired in parallel inside the middle plug to suit my current 2x12" 15R Greenbacks.  I have one I used to use wired in series as well for 2x12" 8R V30s.  You could even make the same cables work for a single cabinet too when that is all you needed by just slipping something insulating over the unused tip, say a null plastic type jack socket which has the terminals snipped off and is insulated around itself.  That way it's just pop on, pull off.

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2)

Just for future reference, here is a quick and dirty method of doing it.  The Input Series and Parallel sockets need to be switched on both the signal and ground lines which isn't too unusual but the output speaker sockets need no switching at all.



Remember if you trace that through that when one of the Series or Parallel input sockets has a jack in it its switches are both open!  And just as the bought unit, they MUST NOT be used at the same time.  Sorry I don't have a clearer symbol for the input sockets but I'm sure you'll get the picture.  If you can't get a double switched mono socket then just use a stereo one and use the ring for the ground sleeve connection, it's exactly the same when a mono plug is inserted. Neutrik have both types in their range as have Rean.  It may even be possible to optimise this to make it more efficient but at least this way should work.

(Still think it's simpler to just have a dedicated lead.    )

Sorry for late response, I am in Italy on vacation right now, BordonBert thanks but although I would agree with you on the fact that salespeople are there for the obvious, but this Palmer PCABM is not sold in any of the stores I where I asked how to get 2 cabs going on an amp with one speaker out. I sort of want to think that their recommending to buying something they don't even sell at those stores led me to believe there was some validity in the claim. I don't mind a $50 price tag, I know I would have made a shoddy wiring contraption and prefer a more clean machined device, looks more pro-like to me than anything I would have build.