New to Valve Amps

[MrAce]

Hi I'm new here but what I've read so far gives great confidence that there are guys here who know their stuff.

Just bought off ebay an PV Classic VT 100 Series. I bought it advertised none working, hoping to learn about Valve amps and to get it working again. Done a bit of research and have discovered a few issues with my purchase.

Pulled the chassis out and checked for obvious damage but found none other than:-

The power cable had pulled out from its clamp on the chassis and cut through the Live lead. Simple repair! I fitted a 'kettle' socket and the beast powered up and appears to work A couple of scratchy pots but apart from that all is good.

There is a tolex bag in the base of the cabinet and two cables hanging from a plug in the chassis. I believe this to be for a reverb tank does anyone know what model was fitted or of any alternative that can be used as a replacement.

The speakers appear to have been replaced by Celestions. Don't think I'll do anything about that.

Also missing the footswitch

Is there anyway to date the amp?

Only other question is that there is no standby switch, does the amp need one if so how would I go about fitting one?

Are there any other mods or should I just sort the reverb out and enjoy?

Ace

[Enzo]

Hi and welcome.

Your PV Classic VT is a hybrid amp. The power amp section is tubes, while the preamp is solid state.

The bag in the bottom shold hold the reverb pan, is it there? Bag empty? The original would have been an Accutronics 4EB2C1B. The two cables with male RCA plugs on the end plug into the two jacks on the reverb pan. Turn the amp on and set the reverb up about half way. Now grab those hanging reverb cables. Touch the tip of each plug. One ought to make hum come out the speaker. The one that hums plugs into the OUTPUT jack on the reverb pan. The jacks are labelled.

Peavey will sell you any part for their products, but you will pay a lot less for reverb pans from www.tubesandmore.com

You can date the amp by sending the serial number to PV customer service. The serial number may have a format like 8A-12345678. The first part 8A means A for amplifier and 8 is the last number of the year. Likely 1978 for you.

You can estimate the date by looking at the date codes on the parts. Look on the controls across the panels, should be numbers stamped into their rear covers. A number like 1377826 means the following
137 - CTS made the part
7826 - part was made in 26th week of 1978

Other parts will have similar 7826 format date codes - look on transformers and larger parts like large capacitors and power resistors.

AMp has lasted 30 years without a standby switch, I wouldn;t bother with one now. if you want it in standby, turn the volume to zero.

I think these are cool enough old amps, but the solid state preamp built of integrated circuits on a circuit board doesn;t lend itself to modification. I wouldn;t say there is a whole lot worth doing to the power amp section. SO enjoy the amp.

If you want to learn about tube amps, read this forum, and consider building a kit amp or find an old "PA" amp like an old Bogen or something and rebuilding it into a guitar amp. There are also project web sites like the AX84 with a proven project design.

[MrAce]

Enzo, many thanks for the reply, I've just finished stripping the hardware of the cabinet so I can give it a good clean. Before I stripped it I quickly checked out everything.

The amp works fine there is a bit of hum/hiss but it's not noticable with any volume. THe Phasor circuitry appears to work fine and it makes some interesting sounds!

Thanks for the lead on the Reverb Tank I will see if I can get one to fill the empty bag in the base of the cabinet.

The serial is 1A-861444 and there is a transformer with a 70xx stamp would that lead you to believe I have a 1971 amp? I still need to check out the serials on the pots. The Celestions are dated '70/'72.

Off to give the tolex a good scrub now. Thanks again for the info.

Ace

[Enzo]

71 or 81. The Celestions are not stock, so they don;t count.

Just contact customer service at PV and ask. There is also a collection of forums at PV, under support. You can find like minded Classit VT owners.