Mini-Mass or Micro-Mass for Pro Jr?

[tap4154]

I've been using a simple L-Pad I made on my PJ with good results, but know it's not ideal and puts a load on the OT if cranked too much (above 8 or so on the amp, with very high attenuation). Have read of folks killing their amps with simple L-pads like mine, diming the amp then just cracking the L-Pad open.

So I'm looking at buying a 50 watt Weber Mini-Mass or 15 watt Micro-Mass. Basically the same price, but I like the two tone controls on the Micro (Low-Mids & Mids-High). Is a 15 watt unit enough for a 15 watt amp? I've read yes and no on various forums, including here. I won't be running the amp above 7 or so.

Also don't see a switch on the Micro-Mass for speaker ohms, even though text says it's good for 4, 8 or 16 ohms. Is it auto-adjusting? Or it's just that an 8 ohm unit is fine to use one step up, or down?


Mini
https://reverb.com/item/4806751-weber-mini-mass-attenuator?gclid=CNSI2bWXldMCFUpNfgod11AIZw&pla=1

Micro
https://reverb.com/item/282059-weber-micromass-attenuator-15-watt

 

[tap4154]

Ah, just found the answer to my speaker ohm selector question on the Weber site.

WHY DO SOME UNITS HAVE IMPEDANCE-SELECTORS, BUT OTHERS DO NOT? On our attenuators that have two (or three) knobs for adjusting the highs and lows, it would be very difficult and impractical to implement an impedance switch. Because impedance varies with frequency, and we are splitting the frequencies into two components (high and low) a global impedance switch would actually interfere with the tone-shaping function. The unit is designed around an 8 ohm speaker motor, but with all the components of the unit working together, it is safe to use on 4 8 or 16 ohm amps.

https://www.tedweber.com/attenuator-faq

Just found a listing by Weber that states; "it is best used on amps 10w or less."

https://reverb.com/item/3425942-ted-weber-micro-mass-attenuator-2015-black-enclosure

l'm thinking if I only run the amp on 6 it should be fine...

 

[tap4154]

Just pulled the trigger on a new Mass Lite, 100 watts. Birthday was a few days ago and I'd been given a little cash, so added a bit... and happy birthday to me!

This one I can use with my Super 210 as well, but it's mainly for the PJ and Exy. Bought it off Reverb (through Chicago Music Exchange) and with a coupon sale they currently have got it for $163 shipped.

https://www.tedweber.com/mass-lite

 

[Silverface]

Is a 15 watt unit enough for a 15 watt amp?

I was going to suggest you simply ask Weber - they are the best ones to can give you a precise answer. Posting this in case others click on the thread.

With currently-manufacturered products questions like this are usually best answered by the manufacturer. The "guitar public" *may* know - or may just like to answer questions randomly!

 

[tap4154]

I was going to suggest you simply ask Weber - they are the best ones to can give you a precise answer. Posting this in case others click on the thread.

With currently-manufacturered products questions like this are usually best answered by the manufacturer. The "guitar public" *may* know - or may just like to answer questions randomly!

Agreed, but there are lots of knowledgeable folks here. In the mean time I read other forums and the Weber page, and chose the Mass Lite. But from what I've read the 15 watt Micro-Mass would be fine with the PJ, but not for full attenuation or when dimed. So for ~$60 more I'll have the safety of a 100 watt unit. Also like the look of the new black/brown ones over the bright red...

 

[Silverface]

Agreed, but there are lots of knowledgeable folks here

Absolutely, but on every forum there are "random answer people" who have no clue what they are talking about. It can be hard to know which is which - that's why when a manufacturer can be asked abut a technical detail IMO it's a safer idea to go to the source.

 

[Paul G.]

I use a Mini-Mass with my JTM45 and 18-watt heads.

It works quite well and I don't miss tone controls. Even at fairly high attenuation, tweaking the treble on my amp is enough.

P.

 

[PCollen]

I've been using a simple L-Pad I made on my PJ with good results, but know it's not ideal and puts a load on the OT if cranked too much (above 8 or so on the amp, with very high attenuation). Have read of folks killing their amps with simple L-pads like mine, diming the amp then just cracking the L-Pad open.

So I'm looking at buying a 50 watt Weber Mini-Mass or 15 watt Micro-Mass. Basically the same price, but I like the two tone controls on the Micro (Low-Mids & Mids-High). Is a 15 watt unit enough for a 15 watt amp? I've read yes and no on various forums, including here. I won't be running the amp above 7 or so.

Also don't see a switch on the Micro-Mass for speaker ohms, even though text says it's good for 4, 8 or 16 ohms. Is it auto-adjusting? Or it's just that an 8 ohm unit is fine to use one step up, or down?


Mini
https://reverb.com/item/4806751-weber-mini-mass-attenuator?gclid=CNSI2bWXldMCFUpNfgod11AIZw&pla=1

Micro
https://reverb.com/item/282059-weber-micromass-attenuator-15-watt

Mini-mass....that's a no-brainer. $10 more for so much more capability. Size does matter..go mini, not micro.

I have an original 50W Weber Mini-mass. I've used it with tube amps up to 40 watts (JTM-45 clone, Dr. Z Rt. 66, Dr. Z Maz-18, Fender Blues Jr. , and even Epiphone Valve Jr) as well as using it as a simulated speaker load when biasing amplifiers on the bench. I never "dime" my amps, running the tubes into clipping, but do run them hard enough to get the clean/crunch tone I want with pedals providing the OD/Dist, and then attenuate them as necessary. The Mini-mass works great and I'm sure the newer ones work just as well if not better. I really like the ability to use any 4, 8, or 16 ohm speaker impedance load, as long as the Mini-mass is set to match the amplifiers output impedance.

 

[tap4154]

Mini-mass....that's a no-brainer. $10 more for so much more capability. Size does matter..go mini, not micro.

I have an original 50W Weber Mini-mass. I've used it with tube amps up to 40 watts (JTM-45 clone, Dr. Z Rt. 66, Dr. Z Maz-18, Fender Blues Jr. , and even Epiphone Valve Jr) as well as using it as a simulated speaker load when biasing amplifiers on the bench. I never "dime" my amps, running the tubes into clipping, but do run them hard enough to get the clean/crunch tone I want with pedals providing the OD/Dist, and then attenuate them as necessary. The Mini-mass works great and I'm sure the newer ones work just as well if not better. I really like the ability to use any 4, 8, or 16 ohm speaker impedance load, as long as the Mini-mass is set to match the amplifiers output impedance.

I'm sure the Mini Mass if excellent, I just like the idea of the 2 volumes, after reading about how they work together. BTW I changed my mind and wanted to cancel the larger 100 watt Mass Lite and get the 15 watt Micro Mass (much smaller unit) but even though it hadn't shipped they said it was too late to cancel, and I could just send it back. So I ordered the Micro Mass too and will give them both a gentle test run/look-see, then decide which one to keep. The Micro was only $84 with the coupon code on Reverb.

The Micro is only rated at 15 watts, but in reality I'll only use it with my 15 watt PJ and 13 watt Exy, in both cases at half volume, so it should handle them both fine. The Weber page says you can use an attenuator with a wattage rating equal to your amp volume as long as you don't dime it then attenuate too much.

 

[tap4154]

Found some gut shots of the MicroMass, MassLite and MiniMass. All seem to use similar speaker motors, but controls have different size/ratings.

Interesting that it looks like the small 15 watt MicroMass has 25 watt 50 ohm controls. I wonder if they rated the unit at 15 watts to be safe, or maybe so folks with 13-15 watts amp would pay more for a larger unit?

MicroMass

MassLite

MiniMass

 

[tap4154]

I emailed Weber asking why the Micro was only rated at 15 watts when it had 25 watt controls, and they responded in like 5 minutes! Turns out the speaker motor voice coil in the Micro is only rated at 15 watts. I do now see all the speaker motors are different as they increase in wattage. I may keep the larger one, knowing this.

Text:

...excellent question, and the reason is that the rheostat isn’t the only thing that has to do with the power handling. the heart of our Mass products is the speaker motor, and the rating of the voice coil itself is only 15w in the micromass. so here is my no-but-yes answer:

It is my policy never to recommend or say that you can use any attenuator that is rated lower than or equal to your amp's output. 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.

If you are simply going to dial an amp up to where it starts to breakup in the clean channel and then knock it down a few dB so the club owner and the sound man are happy, then using a 15 watt attenuator for a 13 watt amp will be ok. However, it is generally not my policy to recommend an attenuator that could possibly be damaged by too much power, so I would caution you in two ways:

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.

 

[homesick345]

I've been using a simple L-Pad I made on my PJ with good results, but know it's not ideal and puts a load on the OT if cranked too much (above 8 or so on the amp, with very high attenuation). Have read of folks killing their amps with simple L-pads like mine, diming the amp then just cracking the L-Pad open.

So I'm looking at buying a 50 watt Weber Mini-Mass or 15 watt Micro-Mass. Basically the same price, but I like the two tone controls on the Micro (Low-Mids & Mids-High). Is a 15 watt unit enough for a 15 watt amp? I've read yes and no on various forums, including here. I won't be running the amp above 7 or so.

Also don't see a switch on the Micro-Mass for speaker ohms, even though text says it's good for 4, 8 or 16 ohms. Is it auto-adjusting? Or it's just that an 8 ohm unit is fine to use one step up, or down?


Mini
https://reverb.com/item/4806751-weber-mini-mass-attenuator?gclid=CNSI2bWXldMCFUpNfgod11AIZw&pla=1

Micro
https://reverb.com/item/282059-weber-micromass-attenuator-15-watt

On the Weber website it is written somewhere that you need to leave a hefty safety margin when using an attenuator. Yes, you need a 50w attenuator for a 15 watts amp, for it to run cool & safe.

 

[tap4154]

On the Weber website it is written somewhere that you need to leave a hefty safety margin when using an attenuator. Yes, you need a 50w attenuator for a 15 watts amp, for it to run cool & safe.

Yes, I plan to keep the 100 watt one. Also found that Weber has a harness to use when you don't have a 1/4" speaker jack. It uses the spade connectors. So I ordered one and I'll be able to use the MassLite on my Champ and Super 210 as well.

https://www.tedweber.com/pv30mh

 

[tap4154]

Decisions decisions... Got them both a while ago and finally can see the difference in size etc. Frankly, I can get better tones out of the Micro, and it doesn't even get warm on close to max attenuation with the amp on 8-10, though I haven't played an extended amount of time yet. With the amp on 6 I love the tone and can turn the MicroMass up a bit. Really, similar tones as my L-Pad, but none of the heat.

The MassLite has a high and low range that makes it very tinny when turned low, but once you turn the left volume up it's back to normal. Seems it gives you a wider volume range when you want lower attenuation. It IS a quality unit IMHO.

But now I can see that I probably wouldn't use the MassLite on my Super 60 at home. Volume would be too high for an apartment with 60 watts into saturation, even with the attenuator just cracked open. But with my PJ, Exy and Champ, it'll be fine - so think I'll keep the MicroMass. I'll play it some more tonight to make sure it doesn't heat up, and re-package the MassLite to send back (only played it a few minutes).

BTW, they need taller feet. Even the larger feet on the MassLite don't raise it above the standard Fender flat amp strap, but that's an easy fix.

Pics:

 

[tap4154]

Well the MicroMass works great with the PJ, but now it's found it's real home on my Exy. With a little dialing in, I can get it to a great clean tone, then with just a bit more guitar volume, a very cool OD at apartment volumes. Seriously, when I play it clean with the MicroMass engaged, then bypass and find the same clean volume by turning the guitar volume down, it sounds the same. Nice thing about this one (and the larger MassLite) is it's really two attenuators in one. Has a low-mid rheostat and mid-high rheostat.

Very happy!

BTW, it still never gets warm, even with the low-mid on 1 and mid-high on 3-6, with amp volume on noon to 3:00. Actually stays cool to the touch.

 

[Larry F]

I actually emailed Ted about this. His recommendation was to use a Mass rated at least twice the wattage of the amp. At the time (two years before he died), his website included that info.

 

[tap4154]

I actually emailed Ted about this. His recommendation was to use a Mass rated at least twice the wattage of the amp. At the time (two years before he died), his website included that info.

That info is still on the Weber site and was echoed in the recent reply from Weber I posted above, but the way I'm using the Micro I think I'll be fine. Again, it has two 25 watt rheostats, and I'm running the amp at about half volume. The unit stays cool to the touch after a half hour of continuous playing. Just don't see anything to worry about with this 13 watt Excelsior using the MicroMass.

Were I running the amp on full volume with both rheostats just cracked open, that would be a problem, but I won't.

Gonna make some cables with RCA connectors to try it on my '69 Champ. That MicroMass is PERFECT for a Champ.

 

[King Fan]

Well the MicroMass works great with the PJ, but now it's found it's real home on my Exy. With a little dialing in, I can get it to a great clean tone, then with just a bit more guitar volume, a very cool OD at apartment volumes. Seriously, when I play it clean with the MicroMass engaged, then bypass and find the same clean volume by turning the guitar volume down, it sounds the same. Nice thing about this one (and the larger MassLite) is it's really two attenuators in one. Has a low-mid rheostat and mid-high rheostat.

Very happy!

BTW, it still never gets warm, even with the low-mid on 1 and mid-high on 3-6, with amp volume on noon to 3:00. Actually stays cool to the touch.

Great research and report. Thanks!

 

[SURF]

Congrats with the new box! At first I have no idea why they used driver motor as inductance, but then I got that they are driver company.

Is the box silent when playing? I see from schematics that the motor is maximum loaded when "low-mids" are at zero. If it will ever burn then there. If it will burn - no problem. The attenuator will still work without it.

I would have add phones output there.

 

[SURF]

Were I running the amp on full volume with both rheostats just cracked open, that would be a problem, but I won't.

You can put rheostats in any position - it doesn't matter. The only part that can burn is the motor. You can easily rewind it. There are not many turns. Or you can disconnect it. Chances are that the sound will be better without it.