Ampeg Micro VR Explain the Gain

BulbousMoses · #1 06-10-2011, 06:23 AM

I was playing around with my Micro VR last night and I realized that I am a big dummy when it comes to the use of the gain knob. What I mean is that I really don't know what it does (other than make the amp louder) Can someone explain what is happening electronically and tonally when you increase/decrease the amount of gain, specifically on the Micro VR..

JimmyM · #2 06-10-2011, 06:44 AM

The gain is just the amount of signal from your bass allowed to travel through the amp. The less gain, the less signal. Keep it low if you want very clean, and crank it if you like a little grind. Fortunately, the Micro VR has a very musical light grind when you crank the gain. Just play around with it and see what you like.

fenderhutz · #3 06-10-2011, 06:48 AM

To add to JimmyM's post. These are my settings I use with a passive P and J bass to get a nice wooly warm Ampeg sound.

Gain 1 o'clock (sometimes a little more)
Bass 2 o'clock
Mid 10:30
Treble 11 o'clock
Master (well what ever volume you need) I usually set it 1 o'clock

Limiter on, -15 off.

BulbousMoses · #4 06-10-2011, 07:04 AM

Thanks guys...that helps me understand things a bit better. So on the Micro VR, if I want a cleaner sound, I can drop the gain down to, say, 9 or 10 o'clock but I'll lose some volume by doing that, correct?

**cheezewiz** · #5 06-10-2011, 07:09 AM

Right...which you can make up for with the volume knob.

pedrodelawasp · #6 08-22-2011, 04:43 AM

Took delivery of my Micro VR stack on Saturday morning. Got to say, I love the looks of the thing. Just in a new flat, and it sets the living room off a treat (we'll see if the missus will let me keep it there...) It seems really well put together, to me anyway, and the lightness will be welcomed warmly by my back!

I generally like to keep my amp sound pretty clean and dubby, using pedals for dirt or to bring in some highs (have an Ibanez PD7 on 'clean' mode, but with overtones at '1' and both bass and treble boosted a little. Gives a great pick tone, and works great for slap, even though I only ever slap when messing about), but I think I'll find myself bringing up the gain from time to time to use the head's grinding capability.

Would love to try this with a 115 cab at the bottom. Anyone tried that?

fenderhutz · #7 08-22-2011, 05:58 AM

Just get another 210 cab. Mixing speakers sizes other than for a 3 way cab is only for aesthetics.

pedrodelawasp · #8 08-22-2011, 04:26 PM

Quote:

Originally Posted by fenderhutz

Just get another 210 cab. Mixing speakers sizes other than for a 3 way cab is only for aesthetics.

Wouldn't the different sizes of the cones mean the cabs would have differing efficiencies in producing frequencies? What I'm getting at, I guess, is that I'd expect a fifteen to put out a little more of the lows
For example, my deceased ashdown mag250 C 115 was much more bottom happy than a mag250 C210 I played through several times.

JimmyM · #9 08-23-2011, 12:13 AM

Quote:

Originally Posted by pedrodelawasp

Wouldn't the different sizes of the cones mean the cabs would have differing efficiencies in producing frequencies? What I'm getting at, I guess, is that I'd expect a fifteen to put out a little more of the lows
For example, my deceased ashdown mag250 C 115 was much more bottom happy than a mag250 C210 I played through several times.

The Mag 115 was designed to push more lows than the Mag 210. Has nothing to do with speaker size and everything to do with the design of the cab and the porting. Speaker size has nothing to do with how much low end a cab has. One of the lowest response cabs on the market is the Ampeg 410HLF as an example.

rustyginn · #10 08-23-2011, 04:35 AM

I know we aren't talking about the same cabs here, but. I like the way a 2x10 and 1x15 sound together, especially with the Micro VR. They enhance each other. Adding a 15 seems to mellow out the sound. When I play a 4x10 it seems almost abrasive. Deeper, brighter, tighter... I'd rather have warm, smooth, and round. I know this is a very vague (and highly opinionated) explanation. For me, this setup is nearing perfect.

beans-on-toast · #11 08-23-2011, 07:05 AM

This is a simplified block diagram of the signal path. The preamp out and power amp in are actually connected but are split into two sections here. They are the two main sections of the amp.

The 15 db pad and the gain are used to adjust the volume from your instrument. Instruments don't have the same output signal level. To compensate for this, the pad switch reduces the input level and the gain does the opposite, it boosts the input signal. This sets the final level that is fed into the preamp. You adjust them to give you the sound that you like with the instrument that is plugged in. You use the clipping light as a reference to help you set that level. The LED is just a guide. Don't let it rule how you set your input level. Let your ears do that. Having the light on will not hurt your amp.

As you can see in the diagram, the volume control is just before the power amp. This sets the overall volume of the amp after the input has been set and the signal has gone through the tone controls.

pedrodelawasp · #12 08-26-2011, 06:18 AM

Quote:

Originally Posted by JimmyM

The Mag 115 was designed to push more lows than the Mag 210. Has nothing to do with speaker size and everything to do with the design of the cab and the porting. Speaker size has nothing to do with how much low end a cab has. One of the lowest response cabs on the market is the Ampeg 410HLF as an example.

Thanks for the input Jimmy, and everybody.

In respect to what you're saying, if I decide to go with a second cab in the future with the Micro VR I expect I'd go with one designed to push the lows, and a 115 would help maintain the portability I was looking for when deciding to go with the micro. Mind you, a 2nd 210 AV would do that bit too. As ever, trying before buying would be the way to go then go for whatever I like the best. Wouldn't mind trying a MAG 115 Deep cab, or a B-115 perhaps.

P.S. One reason I'd be holding off on adding a second 210AV would be the problems of running that setup as documented in other threads on the Micro

pedrodelawasp · #13 08-26-2011, 06:21 AM

Quote:

Originally Posted by rustyginn

I know we aren't talking about the same cabs here, but. I like the way a 2x10 and 1x15 sound together, especially with the Micro VR. They enhance each other. Adding a 15 seems to mellow out the sound. When I play a 4x10 it seems almost abrasive. Deeper, brighter, tighter... I'd rather have warm, smooth, and round. I know this is a very vague (and highly opinionated) explanation. For me, this setup is nearing perfect.

Aesthetically, a very cool looking setup. Great you're getting the sound you're after too.