Load impedance limitations are usually related to the power (heat) dissipation of the amplifier. I mean theoretically you could drive any solid state amp into a dead short if you could cool it properly. This comes down to pulling heat out of the power transistor silicon die in the most efficient way.

Piggybacking on that, current and resistance are inversely proportional, so as you lower your speaker load impedance, the current increases. This is the cause of heat that Nate described.

I've been using my Randall Switchmaster lately and it still is my favorite amp.

I blew up a solid state Peavey head at a show as a teen when I tried plugging it into two cabs not knowing the ohms concept. Blew a transformer. It's been too many years to remember series vs parallel details.

In general I've always understood that more resistance i.e. higher ohms lowers efficiency and therefore volume, but a lower impedance speaker cab than your amp expects over works it

Radio Shack Realistic 100 Watt amp anyone?

losthighway wrote: Sat May 14, 2022 3:15 pm I blew up a solid state Peavey head at a show as a teen when I tried plugging it into two cabs not knowing the ohms concept. Blew a transformer. It's been too many years to remember series vs parallel details.

In general I've always understood that more resistance i.e. higher ohms lowers efficiency and therefore volume, but a lower impedance speaker cab than your amp expects over works it

What amp? Most SS Peaveys i've seen dont have an output transformer, and my general knowledge of SS amp is that one doesnt need an output transformer. An impedance mismatch wouldnt (or shouldnt) cause a power transformer failure.

Dr Tony Balls wrote: Sun May 15, 2022 9:23 am

losthighway wrote: Sat May 14, 2022 3:15 pm I blew up a solid state Peavey head at a show as a teen when I tried plugging it into two cabs not knowing the ohms concept. Blew a transformer. It's been too many years to remember series vs parallel details.

In general I've always understood that more resistance i.e. higher ohms lowers efficiency and therefore volume, but a lower impedance speaker cab than your amp expects over works it

What amp? Most SS Peaveys i've seen dont have an output transformer, and my general knowledge of SS amp is that one doesnt need an output transformer. An impedance mismatch wouldnt (or shouldnt) cause a power transformer failure.

Yeah, I remember the tech was surprised. I can't remember the model. It was late 90's when they were doing 'trans tube technology' stamped on the front. On a quick search it was the Supreme. Apparently they experimented with a few ss amps with transformers. I'm sure your guess as to why is better than mine.

bishopdante wrote: Sun May 15, 2022 11:37 am
It was probably doing some sort of impedance matching to manage the thermals, and drive a high impedance into a lower impedance. Give that a 0.5 ohm load and bad things will happen. The fact that the transformer died rather than the chips is pretty interesting, but I don't like the sound of it much.

If 20 years of memory retention can be trusted it was a parallel two 4 ohm cabs and the head set to something catastrophic like 16 ohms. Basically an after school rock and roll special on ohm's law.

Red-Knob Fender 85 1x12.

Got it for a song as the original speaker was broken and one of the input jacks needed re-seating. Overhauled it generally and stuck a Jensen Neo 12" in it (more to relieve the weight of the cab for hauling around to gigs more than anything) and sounds more than fine. Lovely for cleans with a proper spring tray. Built in overdrive can sound terrible at low levels but you can dial it in to be better using the limiter knob and cranking the volume (has a sort of haywire barking / ripping quality to it that I like but it's an acquired taste). You can bypass the preamp completely if you have a better bet in a pedal etc

Sunn ST-15

These were practice amps that came with Sunn branded guitars in the 90s afaik. Swap the stock speaker, crank it, perfectly decent recording amp for overloaded/ruined sounds. Louder than you might think.

Fender Frontman 15G

Saw someone running one of these at a free improv night and it was more than keeping up with much louder amps, notably someone feedbacking noisily through an Ampeg head/cab. Player was boosting the input with an LPB-1 but otherwise stock afaik. Probably the most surprising amp I've seen in a while considering it's an 8" speaker practice amp thing.

Cheating as it's only partially transistor but Music Man HD 130 212.

My first bedroom amp, music place I got it from could tell I didn't have a clue how loud it was and kept checking if "I was sure it was what I wanted". Gave up trying to get the volume over about 2, and that was reserved for when my folks were out. Finally cranked it at the back of a cavernous old warehouse space one weekend and it shook everything, ludicrously loud. Sold it back to the same shop a few years later to the same dude.

I had a 90's Peavey Transtube Envoy 110, which was big enough to not be a handy practice amp and not loud enough to do the job of a Bandit. Serviceable clean. Gross dirt channel. I had a $30 DS-1 piped into it as was the fashion of the day. Later got a Sansamp GT-2 to pair with it, which sounded rather good, actually. The Input jack messed up so it went into storage at the in-laws' basement where a cat likely pissed in it. When I finally dug it out to work on it the screws crumbled and I said fuck it.

Currently I have a Vox Pathfinder 15. I really, really like it. I got it around two years back for $45 bucks plus reasonable shipping from Guitar Center used online. Everywhere else was asking $150 bucks or more. I don't like it that much. I've not yet gotten it to sound great with my pedals, but I haven't tried too much since it is the amp I play when I just want to sit on the couch and plug straight in. Should try using the filter knob on the rat (which I usually don't) as suggested above. The clean channel sounds great with a smidge of drive dialed in. I even like the overdrive button engaged, which get some fun, thick, nasty dirt. I've toyed with the idea of adding a diode switch for kicks. Great amp for practice without pedals since it sounds good and keeps me from getting distracted with delay, etc. The worst thing I can say about it is that it definitely sounds like a Vox! Which is not bad, I just wish it were voiced more like a 60s Fender.

I really like the Sunn Beta Lead, but the damned thing is just too loud for any setting I was in. It was also the combo model with the funky 2-12 cab. Probably would have sounded better with a different head/cab setup.

I've been often tempted by the Traynor TS series. I do worry that they might be a little too bright for me. Never got to play one in person and demos vary a lot.

Things like Tronographic's boxes kinda make me think a lot of this cool amps might best, most flexibly live on in that format. I've got the parts in my box to build a Beta Lead pre.

Part of what keeps me from diving into a full SS set up is just how the inputs handle dirt. Something about Fender tube amps have spoiled me, even at very low volume. I've had some great luck with JFET based overdrives run rather clean, then hit with a Rat or something. It blooms in a great way I don't get just going into my pathfinder. I've toyed with doing some sort of JFET pre into Class D power amp set up to get a small, portable rig.

Those Quilters look nice, but $$$. But that is anti-SS bias speaking. How does the wattage relate to volume on those things? How flexible is the volume? Are the smaller models flexible enough to test the waters without dropping $$ for a more premium model? It would be cool to have a little rig with a 2x12 cab.