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Post subject: Peavey Classic 20 Mini Amp Head?s
Posted: Mon Jan 04, 2016 7:31 pm
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Anyone try these out? how do they stack up against fender cleans? Head room and taking pedals? Thanks, interested in the 2x12 greenback 25 cabs also if anyone has tried one.


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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Mon Jan 04, 2016 10:27 pm
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kingding wrote:
how do they stack up against fender cleans?


I wouldn't expect much from that pathetic 2 x EL84 output stage. Sonically, it'll more likely resemble a Vox AC15.

Arjay

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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Tue Jan 05, 2016 9:56 am
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The Peavey is configured similarly to a Blues Jr, which is not noted for classic Fender clean tones either.
There are notable differences between even these two however.
The input resistor R11 of the Peavey is 470K ohms, compared to a 1Meg ohm input impedance of a Fender.
There is also an input blocking capacitor, C9 and a high frequency rolloff capacitor C12.
These three components will affect the tone of your guitar in a different manner than a Fender input stage. The extra loading of R11 will dull the sound of your pickups slightly.
The capacitor C9 in the signal path will protect upstream equipment from possible DC damage, but it also degrades the input sensitivity.
C12 does reduce RFI, but it also kills high frequency harmonics.
Since these components are in most Peavey tube amps, it's easy to see why Fenders get their headstart on superior tone Peavey is running with safety gear slowing it down.
The rest of the amp is pretty similar until you get to the feedback
There is this funny band pass filter in the feedback circuit. Its built around C8 & C15. It would create this distinctive hump in the frequency response. Like most filters, it creates phase distortion at the edges of the pass band. This is the designed in dirt that guarantees that you won't be getting anything clean out of this Peavey.
Like I've said before. It's not that hard. If you want it to sound like a Fender, buy a Fender. There are very few substitutes.


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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Tue Jan 05, 2016 10:26 am
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"The capacitor C9 in the signal path will protect upstream equipment from possible DC damage."

Tim, DC from the guitar pickups? Well, I guess pedals may pass some DC (?)


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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Tue Jan 05, 2016 10:35 am
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TimsAudio wrote:
If you want it to sound like a Fender, buy a Fender. There are very few substitutes.


+1000

Arjay

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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Tue Jan 05, 2016 8:35 pm
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TimsAudio
Tim, so you’re implying that if one changes the input components (R11, C9, C12) the amp will sound like a Fender BluesJunior? It appears the Peavey Classic 20 is also cathode biased, whereas the Blues junior is pwr-supply -V fixed bias. Do you think this also contributes to a different sound?

I think both amps have merit. Why not own both.


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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Wed Jan 06, 2016 9:23 am
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Whethet the DC is coming in from a pedal or out from a damaged tube, the blocking capacitor is a standard safety device for engineers.
Fender designs have proven that from a design standpoint, the blocking capacitor is unnecessary.

Changing the input stage will make it sound better. It won't make it sound like a Blues Jr. The comparison was only to describe circuit topology, not tone.
There are some well known mod pages for Peavey Classic 30s that include input changes. Many of these changes would probably benefit the Classic 20 as well.
If you want go for Fender tones out of this amp,
Install the input changes we talked about
Ditch the feedback capacitors in the feedback circuit. Leave the resistors. You may have to adjust their value or use a single resistor. Larger vaules = more gain. Adjust to taste.
Install Fender values in the tone stack, 250pF silver mica, .047/600, and .1uF/600 poly cap
Increase all coupling caps to .02.
This will extend the bass range for the proper interaction to get a decent Fender shimmer.
Put some good JJ tubes or better in it.

The cathode bias won't affect the tone balance vs fixed bias. It does add a compressive effect near max power.
This is an improvement over the older Classic 30s. They have a combined bias, filament, and relay circuit. Every time you turn it off in Drive channel, the relay coil collapses and makes a huge pop at turn off. I'm glad they redesigned it.


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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Thu Jan 07, 2016 3:38 pm
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Retroverbial wrote:
TimsAudio wrote:
If you want it to sound like a Fender, buy a Fender. There are very few substitutes.


+1000

Arjay



Got that right. Nothing in the Hot Rod Series that has the "Classic Fender Sound".
They are what they are. If you like them, that's great too, play whatever does it for your ears.
If you want a new amp with a Classic fender Sound, I'd look at Victoria.

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Post subject: Re: Peavey Classic 20 Mini Amp Head?s
Posted: Thu Feb 18, 2016 6:49 pm
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Peavey Classics are solid amps. I use to own a classic 50. That being said, I would not touch the new classic 20. They are cheaply made chi-com imports.

If you are serious about a Peavey Classic you would be better off buying a USA made one on the used market. Last time I looked they were not hard to find on ebay or craigslist for $200 to $300.


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