MiniMASS 50w Attenuator

Designed for use with 35w amplifiers and lower.


Headphone Output * 

Headphone Output

Footswitch Bypass * 

Footswitch Bypass

Attenuator FAQ * 

Attenuator FAQ

This attenuator has a main volume knob and 3-position treble compensation switch which affect the signal to the speaker. The line out signal is dependent on your amplifier settings.


Impedance selector for 4, 8, 16 ohms, 3-position treble compensation switch, MASS bypass switch, unbalanced line out. The MiniMASS employs an actual speaker motor for realistic interaction between the attenuator and the output circuit of the amplifier. The attenuation is continuously adjustable from about -3dB to over -50dB.


By turning the speaker control to minimum (maximum attenuation), the unit may be used as a dummy load for testing or for DI use.


5.5” x 5.5” footprint (add 1” in front for knob). 3.75” tall. 3.35 lbs basic.


Line Out jack has no volume control and is dependent on your amp volume setting, but we do offer a Line Level Volue Control here:



This item is hand-built to order, to ensure the best attention to detail is paid to its construction.  We build them one at a time, on a table – not hundreds at a time on an assembly line.  This allows us to reduce the margin for error and produce an overall higher-quality product.  Please allow at least 7-10 business days for your order to be built and then shipped.



IMPORTANT NOTE ABOUT HIGH GAIN AMPS: High gain amps such as Marshall or clones (with heavy distortion) are hard on attenuators. Unfortunately, an amp’s volume dial is not a good indicator of how much power is being produced.  Many amps can reach full power at 3 or 4 on the volume dial, so it is a good suggestion to get an attenuator with 4x the power handling. For example, if you have a 50w high gain amp, you should opt for the MASS 200. If you have a 100w amp, you should still go wtih the MASS 200 but you should not crank the amp.

1) do not attenuate too far down. this puts a lot of power through a very small section of the volume rheostat which can cause it to fail

2) also do not turn your amp all the way up.  even if you’re just knocking a little off the top with the attenuator, it’s a good idea to keep the amp somewhere in the middle at most.  it’s best to find the lowest volume on the amp that is the acceptable tone to you, and then use the attenuator to bring it the rest of the way.


CABLES: for combo amps, most people like to set the unit on top of the amp. sometimes there is enough slack in the speaker wire to reach and sometimes there isn’t. these cables will make it work for you: GMC2P and GMC2E If the speaker is hardwired, then you need the PV30MH.

(click the links to view them, and add to your order if you need them.)




9 reviews for MiniMASS 50w Attenuator

  1. Greg

    I have to admit that when I first received my MiniMass I was a bit disappointed. I tried it with a number of amps Fender Concert 1X12, Orange OR-15, Blues Deluxe, Egantor Tweaker and several others and I couldn’t find a sound I liked at all. I was hope to get some good, overdriven power tube crunch and I couldn’t find it anywhere.

    Then I let it sit on my desk for a year.

    Then I had an idea and got it out again.

    I’ve been on a quest for low volume tone for a long time and had almost given up.

    It occurred to me that I might be able to use this device as a load box, utilizing its line out to feed other things.

    OMG. I finally found what I was looking for. I run amps directly into this unit into various DAWs and use a speaker sim plug in and the results are phenomenal. Currently I’m using RedWires cab and mic sims but there are lots of good options out there these days. I’ve also had excellent results using several year old Line 6 Pod Farm cab models.

    So, in the end, I’m using about 10% of the features of this box, but it’s doing exactly what I need it to.

    Now I just need Weber to make a ‘no frills’ version. Just and impedance switch and a bypass switch. Attenuation either at 0% or 100%. I’d buy loads of them.

  2. Sean

    Hey Ted, I just received my MiniMASS 50w this week and absolutely love it! I’m using it with a 15W Mack Skyraider SR-15 tube head. I’ve always loved the sound of the Skyraider, but to get it to really sing it had to be cranked. The Skyraider is a non-master volume amp, so it was impossible to get these great tones at studio volumes, but now I can thanks to your product. The treble boost is a great addition especially useful for when you attenuate down to bedroom levels, it helps keep your sound crisp and clear. Thanks again for building a fine product.

  3. William (verified owner)

    Just got this yesterday and almost missed dinner because I was playing with it so much. I love the headphone out feature as I am a bedroom player. I have my Orange Dark Terror 15 watt tube head running into this right now and can really get the tubes nice and warm while using headphones.

    I use a lot of pedals with my setup so this is great to have a platform that allows me to run everything into my amp, including my modulation pedals through the effects loop and have a headphone out at the end of my chain.

    Also, with the attenuator volume I can dial in some nice bedroom volumes without the headphones while keeping the tubes running optimally. Great product at a much better price than the factory built competitors. Thanks Ted Weber for saving me from eviction!

  4. Pete

    My mesa boogie is too powerful for home use unless you run it very quietly.
    Problem there is that the tubes are then not running properly. Sticking the minimass in to the amp means I can now get the tubes breathing, and crank them up but still maintain sensible decibel volume. With the treble boost switch you can also remove the problem of treble loss at higher gain. So how does the rig now sound ? Face meltingly lovely and also at low volumes. In fact the minimass is getting me sounds which I never dreamed of. I must conclude therefore that this is a very good device and that if you want an attenuator then Ted makes them good.

  5. Michael (verified owner)

    It was a long way til I found my sound, but thanks to the Minimass 50 I finally found it. I play a Vox AC30 and as everyone knows: it’s a damn loud amp. Playing with the band it’s quite funny when you’re louder than the drummer AND the Bassist together. But just funny for a minute or two … in fact it’s just annoying. Two years ago, I tried to attenuate my amp with an EHX Signal Pad – cheap and effective. But it destroyed the chimey sound of the AC30 and made it dull. After hours of browsing the Internet I spotted the Minimass. And hey, the guys of Weber really make a fine Job! With the harness (PV30MH) it’s so easy to install. The sound is amazing, it still sounds like an AC30, and I can’t hear any loss of brillance or heights or whatever in the tone! Within a few minutes I found my personal sweet spot at a reasonable loudness. It just felt like having a new amp. The little box is build like a tank, and the treble boost switch is a great little helper! The Minimass is an absolute must-have for any loud tube-amp. PS: The support from CJ is awesome! [You are welcome, Michael!]

  6. Les (verified owner)

    I’m not one to leave reviews but this has made my playing life 10x better. My wife and I have 2 young kids which dropped my playing substantially mostly due to volume. This has tamed my Bad Cat 30r’s volume but not its growl. I couldn’t be happier. I just wish I bought it 10 years earlier when neighbors were an issue.

  7. Donn (verified owner)

    After owning my vintage Princeton Reverb for many years and rarely getting to crank it to hear it’s magic, I finally purchased the Weber MiniMASS. Now I can sit in my tiny NYC apartment with the amp volume at 5.5 and not destroy my hearing or have the neighbors call the cops.

    Does it sound the same as a very loud Princeton, no. Does it sound very good, yes. No need for pedals, just the amp’s natural break up, reverb, and tremolo. It definitely sounds better than putting an overdrive pedal in front of the amp. And no battery or power supplies to deal with (MiniMass does not require power).

    I’m also using the Line Out to record directly into my laptop via a Zoom U-24 interface. This required installation of impulse responses on my laptop (like any line out would) and the results are fantastic.

    I confirmed with Weber that you can disconnect the amp’s speaker if you have the MiniMASS fully attenuated (even fully attenuated, you still get sound from your amp unless you disconnect the speaker, it’s quiet but there is sound).

    Weber even hand constructed a custom cable to connect my amp to the unit that matches my existing amp/speaker cable.

    There was a slight mix up with the cable delivery but I added the cable after the order was placed so no big concern. Weber was super responsive through the order/delivery process and helped me understand how to confidently use the MiniMASS with my beloved amp.

    Great purchase from a great company.

  8. Dave (verified owner)

    I bought this attenuator to use with my Jcm800 Studio 20 watt head. It works perfectly for me, now I’m able to crank this amp without fear that the sheet rock will melt off the studs!

    I’m now able to get all the great tones and responsiveness of a tube amp cranked! This little attenuator is an amazing little product. It does the job perfectly and for a very reasonable price.

    Some attenuators cost hundreds of $,…and some thousands. The Weber MiniMass does all that I need it to, and it does it very well.

    There’s even a +3 snd +6 db setting to add some treble if needed. Also you have a choice of 4, 8, or 16 ohm settings for the cab being used.

    I am exceptionally happy with my purchase, this attenuator does everything I want it to do, and it does a great job doing it,…..and at a great price,….what more could a person want?

  9. Mark (verified owner)

    As an attenuator, it does a fine job of letting me dial in the amp and get a reasonable facsimile of that at bedroom volumes. A+

    Even more impressive to me is the recording line out quality, it is far superior to the onboard line out of my previous amp! A++

Only logged in customers who have purchased this product may leave a review.