Overdriving solid state amps with the gain control yay or nay?

[scuzzy]

my old Crate CR-285B amp sounds pretty nice when overdriven, gain dimed. but I have to use a booster pedal to get it over the top into the grit. not like a tube amp at all, but has a cool sound to it.

does it not seem odd to folks that many will spend hundreds of dollars on ss overdrive pedals and rave about them, but out of the other side of their mouth claim that only tube amps sound good driven? what am I missing?

 

[bassbrad]

It can be referred to as Saturation and depending on the circuit it can be pleasing or not. The prevailing myth is that only tube preamps sound good saturated, but I find that is not the case as many solid state circuits have a pleasing saturation.

 

[svtb15]

My Genzler MG800 has a SS preamp It sounds pretty nice if overdriven.. Although I always use a clean sound.. The Pearce preamp is SS .. Billy Sheehan used that with great success for years

 

[GreyBeard]

I like the way my pf-500 sounds with the gain on 3/4 and the master on 1/2. All SS nice crunch when I dig in, clean when I don't.

 

[Two-Spirit]

I need a clean sound, I'm never messing with another dirt box if it doesn't have a blend.

 

[popcat]

If you turn up the front-end gain (to "11") and set the overall volume using the master control (which is usually the input to the final), then the front-end clips and essentially turns everything into square-waves. However it will only be a near square-wave with the tone controls at mid-point, otherwise the wave shape changes and can turn very peaky. So, the amp circuit design and tone controls settings affect the type of distortion and the sound. Generally it will not hurt the amp, but the circuits will generate more heat with square-waves, as a result of continuous clipping, than with easier going sine/music waveforms, and this may affect the performance/reliability of the output stage depending on the overall output volume setting.

 

[agedhorse]

Actually, the circuitry generates LESS heat with square waves... this is the principal of switchmode power supplies and class d amp topologies.

 

[bucephylus]

I have to admit that I am somewhat unsure about the level of fascination with overdriven bass tones. I generally get that capability using pedals in front of my amps; but, I also just find that I don’t generally need those sounds a whole lot for my cover gig. I find a good solid clean bass tone gets most of the work done. Even with the SVT, I will tend to play through those in clean mode. I mean if you are Jack Bruce or Felix Pappalardi in an original band where that is your sound, then sure I get it. But, most dance band material just needs clean.

Anyhow, I use the Grizzly pedal when I want to get just a bit of drive for my P oriented tones. That pedal is perfectly adequate in front of a SS amp. I haven’t heard any SS amp yet that sounds good when overdriven; though I trust @agedhorse ’s statement to the contrary; so, they must be out there.

 

[Bassbeater]

Praise for the hooves that stamp out fallacies

 

[blubass]

I also just find that I don’t generally need those sounds a whole lot for my cover gig. I find a good solid clean bass tone gets most of the work done. Even with the SVT, I will tend to play through those in clean mode. I mean if you are Jack Bruce or Felix Pappalardi in an original band where that is your sound, then sure I get it. But, most dance band material just needs clean.
@agedhorse ’s statement to the contrary; so, they must be out there.

This is exactly it. You don't prefer that sound, so you have no need for it. Effects like delay, flanger, and modulation don't even seem to fit the roll of the bass guitar as I learned it, so I would never use those effects or understand their place. Even though I appreciate a good overdriven tone, I myself have several overdrive pedals and wind up never using them at a live gig. I've actually never used any effect pedal other than an HPF and a compressor at a live gig.

 

[popcat]

Actually, the circuitry generates LESS heat with square waves... this is the principal of switchmode power supplies and class d amp topologies.

No. Class-D audio amps and SWPS may be swamping the market, but they are also based on a high frequency Fo and fast edges (switching) that provide efficiency.

However as far as the speaker load is concerned, even with a Class-D amp, an audio square-wave output will have more area under the curve which generates more heat across the load than does a "non-distorted" sine-wave (this should be obvious).

Also, older SS amps are class A or A-B with linear supplies and generally amplify slow fundamentals (especially bass amps). Therefore, the output goes through a sine-wave like linear region with the tops sliced off. The transistor(s) not only experience the linear region but are held on longer due to the clipping which extends the I2R time through the emitter resistors and the load -- creating MORE heat and stress than with a typical sine-wave.

 

[blubass]

Hey @popcat I'm curious what your background in electronics is?

 

[agedhorse]

No. Class-D audio amps and SWPS may be swamping the market, but they are also based on a high frequency Fo and fast edges (switching) that provide efficiency.

However as far as the speaker load is concerned, even with a Class-D amp, an audio square-wave output will have more area under the curve which generates more heat across the load than does a "non-distorted" sine-wave (this should be obvious).

Also, older SS amps are class A or A-B with linear supplies and generally amplify slow fundamentals (especially bass amps). Therefore, the output goes through a sine-wave like linear region with the tops sliced off. The transistor(s) not only experience the linear region but are held on longer due to the clipping which extends the I2R time through the emitter resistors and the load -- creating MORE heat and stress than with a typical sine-wave.

You might want to re-think your math on this (if I am understanding your comments correctly).

I'm not talking about the speaker (and I was clear about this in my comments), I'm talking about the amplifier stage that's being clipped. You take a class A (or it could be an AB) stage and clip it, and the dissipation falls like a rock when it is in cutoff and saturation. The harder you clip the stage, the more time it spends in saturation and/or cutoff and the lower the dissipation.

Of course, the power dissipation of the following stages will likely rise, but that would have to be calculated at each level being investigated. If the output stage is being clipped hard (to the rails), its dissipation will also be lower but if the level is held below the rails the dissipation can increase. The output stage dissipation curve will be different for different levels and waveforms. I spent many years calculating output stage conditions in conjunction with developing SOA protection.

I don't understand where you come up with this comment:

Also, older SS amps are class A or A-B with linear supplies and generally amplify slow fundamentals (especially bass amps).

First of all, I don't know of any bass amps with class A output stages on the market, and class AB amps amplify don't specialize in "slow fundamentals" (whatever that means). Most quality class AB amps have a power bandwidth of 20kHz (or more), far in excess of what bass guitar (and its harmonics) needs.

 

[BuffaloBill]

I always wanted a clean bass sound but recently decided that was all wrong for the kind of heavy blues/rock stuff I play on guitar.
So my little ole 1980 Peavey TKO 80, 112 with "60 watts RMS @ 5% THD into 8 ohms" actually has an awesome overdrive distortion. I can tweak the breakup at any point I like too. Recording at low actual volume with the help of some reverb and echo, it sounds like a giant stack melting down on stage.

I've only tried/bought an EH Deluxe Big Muff, and that's a total fuzz with a blend pot, not a gradual gain induced distortion.
My experience is humbuckers work better for gain induced distortion, guitar and bass.