Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Lectroid on December 19, 2025, 09:46:42 am

Title: Input matching
Post by: Lectroid on December 19, 2025, 09:46:42 am

I have a Fender headphone amp, a Mustang micro.  https://www.fender.com/products/mustang-micro?variant=45940688781534 (https://www.fender.com/products/mustang-micro?variant=45940688781534)

I want to plug its headphone jack into a DR-ish guitar amp so I can hear it in a room.  If I turn the headphone amp down really low, is this even possible?  Without hurting or stressing the amp?  That's my question.   Here's some specs from Fender:

Output power:               30mW/channel
Headphone impedance:  > 16Ω

Has anyone ever tried this?  Is it feasible?  Is there a (simple?) buffer circuit that might better match the two power levels?

Thanks for any guidance you can give.

Title: Re: Input matching
Post by: SEL49 on December 19, 2025, 10:18:21 am

Quote from: Lectroid on December 19, 2025, 09:46:42 am

I want to plug its headphone jack into a DR-ish guitar amp so I can hear it in a room.  If I turn the headphone amp down really low, is this even possible?  Without hurting or stressing the amp?  That's my question.   Here's some specs from Fender:

Very doable. Just start with the headphone amp turned down really low. No need to be concerned with matching impedance or power levels.

Title: Re: Input matching
Post by: pdf64 on December 19, 2025, 10:19:08 am

Don't worry about it, you won't damage anything.
Just try it and see what you get.
You'll need both stereo sides tip and ring connecting to hear both.
I suggest to plug them into high and low inputs of the same channel, then they'll get mixed together nicely.

Title: Re: Input matching
Post by: Lectroid on December 19, 2025, 10:35:02 am

@pdf64, @SEL49,

Thanks guys.  Appreciate the quick answers.  I'll give it a shot and see what  blows up.  :icon_biggrin:

Quote

You'll need both stereo sides tip and ring connecting to hear both.
I suggest to plug them into high and low inputs of the same channel, then they'll get mixed together nicely

Actually, the headphone amp output is already mono, pre-mixed at the 1/8" socket.  I found a 1 ft cord with 1/8" plug on one end that plugs into the headphone amp, with a 1/4" female socket on the other end.  I plug a wireless transmitter into the female 1/4" socket, and plug the wireless receiver into my amp du jour.  Also added velcro to fasten the BT transmitter securely to my strap. 

This gives me some basic amp/cabinet/effects choices right on the guitar, no pedals.  Sound quality of the MM and effects is not pristine but it's sure convenient.