Technical question: How is this possible?

[Bob Zaod]

Really digging my Blackstar HT-20 head. I think I have become a Blackstar whisperer. Anywho, I decided to try it as a tube power amp for my Helix LT by plugging straight to the return like I do with my Spider Valve and every other amp I have tried it with BUT when I do that there's no output at all. This amp does have a master volume that should control the overall level after I set my level on the LT but no matter what I do I can't get it to make any sound. Thought maybe plugging in the footswitch and changing channels would help but nope...nada. So I hit the fx loop jacks real good with DeOxit and air and made sure to spray some on a patch cable and work it in and out a bunch. Still nothing.

Here's the kicker. It works fine using 4cm! How is that possible?

 

[JiveTurkey]

Plug a dummy cable into the send and see if it works for you.

 

[la szum]

Have you tried sticking a 1/4" cable in the FX Out/Send but not connecting it on the other end to anything, and then
try running the LT into the FX RTN?

 

[Ed DeGenaro]

Put a dummy plug in the send jack and try

 

[Bob Zaod]

Plug a dummy cable into the send and see if it works for you.

How the F**k did I not think of that? HAHA thanks! Gonna try it.

 

[Bob Zaod]

Plug a dummy cable into the send and see if it works for you.

Tried several types of 1/4" adapters and no change.

 

[la szum]

Some kind of pre-/post- setup inside the LT creating an issue?

 

[Bob Zaod]

I mean it's not a big deal but just sticks in my craw a bit. The master volume and presence on my Spider Valve make it so I can get great tones at any volume. I just wanted to see what it sounded like with the Blackstar.

 

[Bob Zaod]

Some kind of pre-/post- setup inside the LT creating an issue?

Nope I have the Blackstar sitting on top of my Spidervalve and if I just move the cable to the SV's return it works as it should. The out is set to line. The Blackstar does have a button for line or instrument on the FX loop but neither button position helps.

 

[James Freeman]

Did you try a jumper cable sent to return?
Try some DeoxIT in the return jack and plug a 1/4" a few times.

Try pushing the 1"4 harder, some jacks have TRS with two contacts to disconnect the circuit, you might reached only the first 'click'.

 

[Bob Zaod]

Did you try a jumper cable sent to return?
Try some DeoxIT in the return jack and plug a 1/4" a few times.

Try pushing the 1"4 harder, some jacks have TRS with two contacts to disconnect the circuit, you might reached only the first 'click'.

I did clean it out really good. It's definitely pushed in all the way and I tried stereo and mono dummy plugs on the send but I havent tried a TRS cable to the return yet. may try that next.

 

[James Freeman]

No I mean the return jack is TRS, the cable should be standard mono TS, but you've already tried that.

Do you have a channel switching pedal plugged in? Try to unplug it form the amp.

 

[Bob Zaod]

The only sound I can get out of it is a POP when I either hot swap cables in the return or when I change outputs from/to line/instrument. Also when I changed the main volume knob to control XLR only.

 

[Bob Zaod]

No I mean the return jack is TRS, the cable should be standard mono TS, but you've already tried that.

Do you have a channel switching pedal plugged in? Try to unplug it form the amp.

yeah I have tried it with/without the channel footswitch. This is driving me nuts now LOL

 

[Bob Zaod]

Guess it's time to put it on the bench and have a looky look

 

[James Freeman]

Okay last test, plug your guitar directly into the fx return, careful it might be super loud.

 

[jellodog]

Bob, if you have nothing plugged into the input, could it be that the amp is going into standby mode when you're using the FX loop only?

From the manual:

https://blackstaramps.com/wp-content/uploads/2021/08/ht5r-mkii-handbook.pdf

 

[Bob Zaod]

Nothing sticking out to the naked eye. R26 is missing but the trace terminates right after it.

 

[JiveTurkey]

Try @jellodog trick

 

[Bob Zaod]

Bob, if you have nothing plugged into the input, could it be that the amp is going into standby mode when you're using the FX loop only?


View attachment 8180

https://blackstaramps.com/wp-content/uploads/2021/08/ht5r-mkii-handbook.pdf

Hmmmmm