Speaker load for Peavey Classic 30

[smarmy]

Recently purchased a Peavey Classic 30 amp, put my Fender Deville on the shelf, just plain sick & tired of the brittle uncompromising sound of the Deville...turn it up too loud, turn it down can't hear it...heavy as a Volkswagon too. The Classic 30 is small as a lunch box & weighs in @ less than 40 lbs, delivers great tone (already made the tube upgrades, plan on OD channel mods/tweaks in near future..also need to add standby switch ASAP

Question is: what sort of ohm load should I have on an external speaker cab for my Classic 30??

Rating on back of the amp says "16 ohm minimum load" the external speaker jack is labeled "external speaker".

Have been debating whether to put a 210 cab under or a 112. Assume if I go w/the 112 I have to go w/16 ohm??

Can't begin to decribe my confusion as to parallel/series wiring of 210 cab

Wouldn't be stuck like this if Peavey hadn't discontinued their 112E cab, would simply grab one & hook it up. Now I'm left w/buying a cab from another manufacturer...those guys in the suits screw things up everytime (IMO

SOMEONE throw me a lifeline on this impedence thing, it's driving me nutz!

[tubeswell]

Welcome to the classic 30 club

Welcome to the classic 30 club - I've had mine for 4 years, and love this amp - its capable of easily being turned into a tone monster with a weeny bit of soldering and a screwdriver. I know Peavey gets a bad wrap at times, and the C30 PC board design is damn fiddly to work on, but inspite of these minor drawbacks, I have so far found mine to be sooo reliable (touch wood) and ya just can't beat its value for $$$$. Its a tried & true workingman's amp.

After I started doing the Blue Guitar mods to my C30, I've decided its a keeper for eva. One mod I definitely recommend is the Tone Stack mod (which is the first mod I did to mine after trying several different tube types - NOS 5751's in V1 and V3 and NOS 12AT7 in V2, and different speakers, eminence, celestion and then more recently custom made Bulldog variant-things with Alnico magnets). So heres the tone stack mod I did, (Courtesy of Mr Ahola)

Boost Cap (C11) replace with 390pF Polystyrene Film (w/ AluminiumFoil) or Silver Mica
Treble Cap (C14) replace with 330pF Polystyrene Film (w/ AluminiumFoil) or Silver Mica
Bass Cap (C18) replace with .047uF Polyester film Cap
Mid Cap (C19) replace with .022uF Polyester film cap
Slope Resistor (R19) replace with 56K
Boost switch resistor (R12) replace with 2.2M
And replace R41 with 120k

This gives a sweeter classic bluesy tone and definitely enhances the different p/up selection positions on my Strat.

I have also done other slightly more finicky mods like adding Master Vol, presence and resonance controls, which all improve the amp's versatility, but definitely try the Tone Stack ones first and see what you think. They are relatively straightforward, and improve the tone outta sight - it becomes quite a boutiquey-sounding little amp.

On the C30 combo amp, the internal speaker connection is wired to the 16 Ohm Output Transformer tap, and the external speaker connection is wired to the 8 Ohm tap. Both the internal speaker and the extn jack are wired to run in parallel, so when you plug an extn speaker in, there is a switch inside the extn socket that switches both the internal speaker and the external speaker to the 8 Ohm O/T Tap. If you are running a 16 Ohm internal speaker, when you plug the extn speaker in, then you should run a 16 Ohm extn speaker, because 2 x 16 Ohms in parallel = 8 Ohms. However, by disconnecting the internal speaker (and making sure the internal speaker wires are taped up so as they don't short onto the amp chassis or any other ground in the amp or onto each other) you can then plug an 8 Ohm speaker into the extn jack.

I have wired the internal speaker jack to a socket I installed on the underside of the chassis, and wired a plug to the internal speaker, so I can either run the amp as a head, or with 1 X 16 Ohm speaker/cab (in the 16 Ohm socket), or 2 x 16 Ohm speaker/cabs (one in each socket), or 1 x 8 Ohm speaker/cab in the 8 Ohm socket - which increases the versatility of the amp. If you are going to do this, make sure you ground the proper internal speaker wire to the chassis when you hook up the new socket, and not the wrong wire.

[zain]

classic 30 impedance

This is what I don`t get....

internal speaker is 16 ohms right?
plug in 16 ohm external speaker.....then...
if wired in parrallel then total ohms would be 8..but if the switch inside the ext socket switches both ext and int speaker to 8 ohms..then the total ohms when wired in parallel would be 4?

franrif@yahoo.com

[Enzo]

No. there is one output from the amp...period. You can connect one speaker to it - the internal - or two - internal and external togther. 16 ohm internal with a 16 ohm external makes an 8 ohm total load. Plugging anything into the external jack switches THE amp output to 8 ohms, which is exactly what you need.

The jacks are wired together, just the external jack has the tap switch.

And yes, you can plug an 8 ohm speaker into the external jack and disconnect the internal speaker and tape the wires for an 8 ohm load as well.

[zain]

classic 30 ohms,etc

I see..it is starting to make sense now....one more question though...

Like you said..when you plug a dummy switch into the ext jack THE AMP output switches to 8 ohms...however if you do this - all you are running through is the 16 ohm internal speaker ? Does this match up?


I `ve been doing this out on gigs and it really does change the sound of this great little amp.

[Enzo]

Well, no. Your 16 ohm internal speaker will be running off the 8 ohm tap of the amplifier output transformer. This is not likely to hurt the amp really, but it is not matched up at all. Most amps are just fine one "step" off on the impedance. Marshalls seem to be more sensitive to it - and expensive.