Harley Benton PA-100 attenuator vs volume mod for PRS MT15

filip989

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Nov 28, 2020
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Ok, one more MT15 thread for me, promise it's the last one

Anyway, loving the amp but as everyone says, it's too damn loud, in my case it's primarily because of the lousy volume taper.

With 3 small kids and no designated music room, I can barely find an hour to olay it at home every couple of days and even at the rehearsal, I barely hit the 9 o'clock until I got over the drummer. Extra question regarding this, it sounded fairly fuzzy and grainy for the first 20-30 minutes. Later it was great. Checked the bias, one tube was at 30.2 and the other 30.7
I lowered it a bit so both are now just under 30 mV, measuring 29.2 and 29.7. Never biased an amp before so I have no clue if this was even needed or if it would make a difference, but since it's so easy to do on this amo, thought I'd give it a try. Thoughts on this? Would the amp sound better quicker if volume was above 9 o'clock?

So for the mail question, I didn't find any content on the PA-100 attenuator here. It should be fairly similar to torpedo captor in regard it has a dummy load (4, 8 and 16 ohm) and has an xlr di for cab sim (I was always a pretty straightforward tube anp kinda guy, so have no idea what exactly this means).

I'd use the attenuator to be able to dummy load the head and connect it to the interface and play over the headphones at home through DAW. Maybe to record something every now and then. I'd maybe use it for rehearsals if I find the sound ti be better. Same goes for small gigs. Not having to take my box from home to rehearsal and back would also be a plus. It's 3 times cheaper than a captor, so for my use, I honestly don't wanna even consider paying more. Just wanna know if anyone has used it and if it was OK and if everything I wanna use it for is doable.

Alternative to this is a volume pot mod. I found a few threads contemplating this, but I cannot find any proven mods. Has there been any? I'm good with soldering (soldering my own cables and made a few pedals), but I'm not so good with theory behind it, so would need to know WHAT to do and then I'd know HOW to do it. I presume this would void the warranty, and since the amp is less than a week old, I'd seriosly consider if this would be worth doing.

That's all, it's a longer post but hopefully the results of it would make me 100% happy with the amp.

Cheers!
 
Hey there Filip, I also have the small beast, love the MT15 ... regarding the bias, it is ok as long as it is 25mV and above, up to 30mV PRS says ... you can also go higher (30-40mV), but people say that with higher bias the power tubes could last a bit less time.

Regarding the attenuators ... have not yet taken that path, but I feel you, the BAD volume pot taper is annoying indeed. Was also thinking about buying one, but have not decided yet, and it should help with the issue. One other way of bringing the volume down is using another OD pedal like Carl Martin Plexiranger (I'm using it) going to clean channel and you can regulate the volume with the (better tapered) clean channel volume knob and the level knob on the OD pedal. That way it is much easier to regulate volume.

Rock on! ... but very silently so you do not wake up the kids ;)
 
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Hi Goran, thanks for your reply! Was just in Ptuj this morning to buy a v30 cab

I was briefly using my friend's 1936 with G12T-75's, which I didn't like on low volume at all. I tried it with v30 at half power setting, and it's a much more pleasant sound at bedroom level. At least now I can play at home with having a decent sound. I'll still get an interface and an amp sim for late night playing.
 
Hi Goran, thanks for your reply! Was just in Ptuj this morning to buy a v30 cab

I was briefly using my friend's 1936 with G12T-75's, which I didn't like on low volume at all. I tried it with v30 at half power setting, and it's a much more pleasant sound at bedroom level. At least now I can play at home with having a decent sound. I'll still get an interface and an amp sim for late night playing.
I see we come from the same beautiful part of the world ;) ... regarding the speakers, the V30s are the way to go with this amp imo, it really makes for a good chugah-chugah sound while retaining a good clean sound, although I swapped one of the V30s for a Jensen Electric lightning in my 2x12 cab to tame the sharp hi mids just a bit and this far I am satisfied. But I did notice the sound from the Jensen to be a bit more present than the V30, but I am still using the original modular 2 way input (mono/stereo - 8/16Ohm), so the connector could have to do with it, will wire them directly together the next time I'll be opening the cab, maybe I'll install another single direct input for that. I took quite some time to choose which speakers I want to use with the amp, and it can make a big difference in the way your guitar sounds. But you need a silent rig, so attenuation it is. The guys on the forum will surely know about that more than me.

Cheers!
 
I wouldn’t mod the amp, but also wouldn’t go for a cheaper load box like that. If I had tube amps I’d spring for one mid-high end load box with IRs and that jazz.
 
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