Hoffman Amplifiers Tube Amplifier Forum

Other Stuff => Solid State => Topic started by: Duncan on September 02, 2025, 02:19:23 pm

Title: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: Duncan on September 02, 2025, 02:19:23 pm
I recently picked up a Dean Markley RM-150-DR (150 watts output) and all of my cabs are 100w cabs. Before I go about building a simple 16/8 ohm power soak box (switchable, loaded with 100w 16 ohm and 100 8 ohm resistors to effectively reduce the amp to 75w max output), I wanted to check in here to see if anyone had a more permanent way of knocking down the 150w output to 100w or so (swapping out transistors, etc).

Anyone have an idea? And no, I don't have a schematic for this amp. It apparently doesn't exist on the internet.

Thanks!
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: shooter on September 02, 2025, 02:56:10 pm
in the SS world no schematic makes things near impossible to "guess"
I take it the volume knob isn't a solution???
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: Duncan on September 02, 2025, 03:14:02 pm
in the SS world no schematic makes things near impossible to "guess"
I take it the volume knob isn't a solution???

Oh the volume knob is 100% my first line of protection, but I don’t know at what point the amp would be putting out more than 100w.

Knowing next to nothing about SS power amps, I had convinced myself that the transistors could maybe be swapped out for different ones, but now that I type it out, that sounds too easy/simplistic
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: pdf64 on September 02, 2025, 05:46:20 pm
With solid state, as load impedance reduces, power output increases.
So at a guess, 150W at 4 ohms may be 100W at 8 ohms and 75W at 16 ohms.

I really doubt it'll be 150W with a 16 ohm cab.
So it might be safe to use.
But, always bench check, don't assume.
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: scstill on September 02, 2025, 05:48:52 pm
Why can't you just play into the 100w cabs just don't turn amp volume up to 10.
I also understand that SS amps are more forgiving on mismatching impedance.
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: shooter on September 02, 2025, 05:50:39 pm
100Watts of what electrons dissipating or ear-drums hurting??


swapping out transistors is pretty simple, it's all that tedious specification stuff that gets complicated.  hence a schematic, parts list......
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: scstill on September 02, 2025, 06:32:12 pm
these days my ear drums hurt at <5 tube watts

having said that is there a "standard" as to the loudness difference between tube and ss wattage??

Here is what Gemini says...
"A solid-state amp needs roughly two to three times the wattage of a tube amp to reach a similar perceived loudness, meaning a 50-watt tube amp is often compared to a 100- to 150-watt solid-state amp, though this is a subjective comparison based on tone and distortion characteristics, not pure volume. A key difference is a tube amp's smooth, gradual distortion and compression at higher volumes, while a solid-state amp's distortion is often harsh at high levels."
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: acheld on September 03, 2025, 10:37:53 am
Gemini stole that answer from this forum!
Title: Re: Unfamiliar with solid state amps, so maybe a dumb question...
Post by: scstill on September 03, 2025, 02:03:01 pm
That's what AI does, it "steals" knowledge... but its good that it shares, maybe the credit should be provided. Its very easy for me to find info via AI.

In the AI thread on this forum we talked about what happens when AI runs out of info, do they create new knowledge or just repurpose old info.