TM 36 redbox

Hi there.

I've had this amp now two months after my Marshall dsl blew up and it's still waiting to be repaired. I love the tm36 it's a fantastic amp. But I'm not altogether sure how the Red box is supposed to work. I know I need to direct out with a xlr cable into a desk, but do I need to have the amp connected to the speaker still? I've looked at the manual, but nothing is clear about how to use it. If anyone can assist and explain to me that would be great. Thanks Stevie

TM36 Manual wrote:Note that if you choose to mute the amp, you do not need to connect a speaker to the TubeMeister 36’s SPEAKER OUT. Designed to enable silent recording, this option provides the full signal to the RED BOX output. To protect the power amp, TubeMeister automatically engages this mute circuit as soon as the plug is pulled from the SPEAKER OUT port.

You shouldn't need a speaker connected to use the Redbox Stevie.  You just make sure to set the Power Soak to Speaker Off, (that's the crossed out speaker switch on the back.)  That way the power soak acts completely as the output load protecting the output stages of the amp and allowing the output valves to be hard driven giving you great tone.

Would I need to use some speaker impulses or does the red box have a speaker simulation?

The H&K Redbox and similar dedicated amp systems have speaker simulation built in though that is not to say that it can't be bettered of course. The trouble is you can't switch the speaker simulation out of circuit (as far as I know) so any other cabinet modelling you add would be on top of the H&K and that could sound great or awful. That said, it is rumoured to be pretty good, H&K are always pointing out that they were the inventors of the system. I have to admit that the Redbox is not something I've ever really used in any critical way so I don't really have a good picture of it in use, maybe someone else can step in here and give us an idea of how good it works in practice? The TM series has only a fixed single cabinet choice but the GM36 has a Modern/Classic switch and the GM40D expands that to Vintage/Modern and Small/Large selections.

Ok thanks.

Well I've got it connected to this SDvdiNsUoSJACIlTqlgjrkGTSQv7ehFGMiMl0JKJLf_FO1RgrbMiz_O0NxFxoCGBfw_wcB, a behringer xenyx analogue mixer, the sound is very weak and quiet.

That looks like it should be a link you've posted but it has come up in my browser as gobblredygook Seelgs. If it is, could you put it up again using the link button on the post toolbar? (The little chain icon.) Just use that and paste in the URL.

I would assume your Xenyx has the ability to take mic level and line level signals in and you have it set to Line? Though if not that should give you overload not a weak signal. Also make sure that any microphone Phantom Power is turned off on the mixer. Are you using a compatible cable with correctly wired XLR at both ends? The H&K Redbox gives you a +ve and -ve balanced signal out which is best used with another balanced input, but it can be wired to use a single sided jack plug at the other end. I have known people to get problems when they try to wire the Balanced XLR to go into a single ended jack socket at the mixer.

I have the correctly wired xlr cable. Phantom power is off. There is no change to any volume, amp or mixer. The mixer just becomes more noisy as I turn the master on the amp or volume on the mixer. It is set to line level.

Ok, so you have XLR termination at both ends in a good cable. Noisy is odd. Do you mean noise as in high frequency hiss generated by the circuitry or as in hum picked up from the mains etc.?

One of the advantages of balanced line transmission is it's rejection of noise. It is specifically used to allow clean signal transmission in very noisy environments, and not just audio stuff, more demanding types of signal transfer. If it is a hum pickup type of problem it really points to something being wrong in the balanced signal setup. Neither of the two signal wires in the cable, lines 2 and 3, should be connected to ground, they should both terminate with the same polarity terminal at the mixer input. The ground wire on line 1 is a separate issue and plays no part in signal transmission.

If it were me I would start by swapping out the cable just to rule it out absolutely. Or use it in another role with a microphone maybe. Just make sure you are testing it in balanced mode.

No problem I can test.