Frequently Asked Questions (FAQs)





Q1: My Plush amp's/cab's serial number is nnnnnnn; what year was my amp/cabinet made?

A: This is a tough one, and short of various inspection stickers, and reliable transformer codes and pot codes, there is currently no definitively reliable way to determine an accurate date based on serial numbers alone.  Pretty much it seems that Plush existed for a period from 1968 to 1972 (or so) so that would pretty much be a good start.  From there, you can get a better idea by using the numbers found on the potentiometers in the amplifiers.  These are great for dating the *earliest* the amp could have been made as the amplifier could not have been made before the components in it (barring replacement bits).  I have seen date code ranges of 2 years in some of the amplifiers that I have looked at.

These eras and their approximate and relative date ranges are as follows:
- 1000 and 1060 series.  These were made during Plush’s entire existence so these are the hardest to date.
- 3000 and 4000 Series amplifiers.  They only show up in the 1971 catalog, I haven’t dug through enough of these to feel confident that they are all from this era.
- Combos.  Again only seen in the 1971 catalog.  
- 8000 series.  Still unclear if these left the prototype stage.  I have only seen one in person.

The cabinet dating would require you to look at the speakers and see if they have date codes on them.  Most of the cabinets seem to be front loaded, pulling the grill cloth off can be a pain, so knowing that the date range is only a few years, that should be good enough.

Q2: How much is my Plush amp/cab worth?

A: As much as you can get for it. Seriously, the best way to determine value is by watching how much amps and cabs fetch on eBay. There really is no hard and fast method of appraising Plush equipment; they've spent far too much time as “Kustom wannabes” though it seems that the 1000 and 1060 amplifiers get the most money as they are the closest to Fender in sound.

To a great extent, condition, originality, color, and, especially, model determine price. For example an 8000 amp in any condition is probably worth the most to a collector out there, but the 3000 and 4000 series seem to have not fared as well as their originally cheaper brothers.

Q3: What's models are original Plush designs and which are “Fender Copies”?

A: Plush amps of the 1000, 1060 and combos from the 300 and 450 series are the ones that most match Fender in design. The larger amplifiers are quite unique for that time period, with the 3000 series using 6 6L6 tubes (Fender didn’t do this until the late 70s with the Super Twin), and the 4000 series with 4 6550, and the monstrous 8000 with 6 8417 power tubes inside.  

Q4: How do I know if my amp has a "passive" tone controls?

A: As far as I have been able to tell, all Plush amps use Passive tone controls.

Q5: What kind of speakers are in my Plush speaker cabinet?

A: Plush never made its own speakers; instead, Plush used several speaker makes in its cabinets. The ones that the literature suggests were CTS, Emminence, JBL, Electro-Tech, and Electro-Voice (EV).  

If the speakers in your Plush cabinet or combo are not one of the manufacturers mentioned above, they are most probably not the cab's or combo's original speakers.

Q6: I want to see if my amp powers up, but I don't have a speaker cabinet. Can I just turn on the amp and see if the tubes light up?

A: You can do this, but only very briefly, a few seconds at most. According to Mark Huss, " As long as nothing is plugged into the output jacks, you should be fine. Most tube amps automatically short the output jacks if nothing is plugged in. It's much worse (and potentially fatal for the OT) if you have a speaker cable plugged into the head but not the speaker. Unlike solid state amps, tube amps are much happier with their output shorted then open-circuited."

So, always, always, ALWAYS turn on a tube amp ONLY when there is a speaker cable connected between the amp and a cabinet! Nothing will trash an output transformer like NOT doing this. Be nice to your Partridges and they'll be nice to you.

Q7: One of the speakers in my 4x12 cab buzzes when I play; do I have a bad speaker?

A: Maybe... but before you assume the "buzzing" means a bad speaker, check some things first.

Check all the bolts securing that speaker and make sure they're snug. A loose bolt can cause the speaker's frame to make all sorts of funny sounds. If, alternatively, you have wood screws securing the speaker, check if they're loose. Wood screws lose their grip after a while, and bolts and T-nuts are the best for securing speakers. Also, make sure the speakers have gaskets between their frames and the baffle board. Metal-to-wood contact can cause noises as well.

After you check these things, make sure there's nothing lying/wedged/stuck in the space between the speaker's surround and the speaker's frame, such as a small piece of wood, or a pebble, or a small section of stripped wire insulation, or something like this. It's amazing what strange buzzes and sounds a tiny piece of stray junk can cause when it's stuck inside this space. Also check for a small tear in (or a separation between) the surround or (and) the cone, which can cause a buzzing sound.

If the buzzing is still there after you've checked all these things and everything is okay, try moving the speaker to a new position (up, down, left, or right) and see if the sound travels with the speaker.

If the buzzing goes away, problem solved. If the buzzing travels with the speaker, this speaker might have a problem. And if the buzzing doesn't travel with the speaker, there's a good chance the buzzing is coming from something else and not that speaker... like a separation between the plywood's laminations, for example.

Q8: When I play through my amp and cabinet, I hear a "ringing" sound coming from amp head and the speakers; what is this?

A: This might be caused by a microphonic tube. As tubes age, their internal components loosen a bit and can rattle. To check this, isolate the head from the cab by putting the head on the floor or putting something between the head and the cab, like foam or a folded blanket.

If the ringing sound goes away when you isolate the head from the cab, this probably means the tubes are microphonic, and you have three choices: 1) do nothing and just live with it; 2) replace the tubes with new tubes; 3) isolate the amp from the cab when you play. A good solution for No. 3 is to get Sorbothane footers that virtually eliminate vibrations between the head and the cab. They aren't inexpensive, but if you want your rig to sound good, and don't want to replace your "vintage" tubes, they're a great solution.

(You can also check for microphonics by very gently tapping a tube's glass bulb; if the tube is microphonic, you'll hear it when you tap the tube.)

Q9: My amp’s covering is pretty ratted, where can I get it fixed?

A: Hard to say.  Your best bet would be an upholsterer who specializes in car interiors or old furniture.

Q10: I keep hearing and reading horror stories about amp heads being ravaged by shipping companies. Any suggestions for shipping amp heads?

A: Please note that these are just my opinions; nonetheless, here they are...

1. Always ship FedEx; offer to a seller to pay extra for FedEx shipping. It's worth it.

2. Label tubes and tube sockets in pencil (so they can be erased later), and remove all tubes prior to shipping. Ship tubes separately. If selling an amp, make it clear you'll do this in your ad and/or before you sell it, and especially do this for combo amps where tubes can be sheared off by a flying speaker. This JUST happened to a friend here in ABQ: the 12-inch speaker in his combo amp broke loose and smashed his tubes.

3. Double box your amp and surround the inner box with a) bubble wrap... the larger bubbles, or b) foam or foam peanuts. NEVER send a heavy amp in just one box, unless it's the original box with the original packing material. ALWAYS write FRAGILE on the box's top and sides.

4. Insure the amp (and the separately shipped tubes) for "true value" if this is more than what you paid. Insuring only for the price you paid can get you into trouble. A good deal is only a good deal if the amp arrives unscathed, whereas a $500 amp that you paid $250 for and insured for $250 will only get you half of what it's worth.

5. Put the shipping label on the side of the box you want to face up. Label this side of the box "TOP" and also write "THIS SIDE UP." I've seen way too many boxes with labels on the sides; remember, delivery guys will place a box so they can read the label easily. And for what it's worth, on the bottom of every box I ship I also write "IF YOU CAN READ THIS THEN THIS BOX IS UPSIDE DOWN."

Q11: I noticed my Plush amp has no impedance switches, what should I use for the load?

A: Well this is hard to say.  Since there is not much information out there, I would go by the speaker cabinets that I have found.  Seems that they are mostly 8 ohm speakers, suggesting that the small amplifiers want a 4 ohm load (2 speakers in parallel) while the bigger amps actually switch internally the impedance based on the number of cabinets that are plugged in.  You must go in order with the 4000 series amplifiers in terms of which jacks you plug into.

Q12: I keep hearing people say Plush amps don't have much gain but are capable of lots of volume. I thought gain and volume were the same thing...?

A: What you've heard is sort of correct: Plush amps are theoretically capable of providing some gain, but are definitely capable of providing lots of volume. But what you thought about gain and volume needs a little clarification, because gain and volume are not exactly synonymous.

Gain is the amplifying factor of one or several stages of an amplifier, which is applied to the input signal. In an amplifier, the gain is subject to attenuation by means of the signal path's components. What is referred to as gain in an amp is the overloading of one stage by a preceding stage. Subsequently, a control that can cause this effect is called a Gain control and can affect several stages at once or just a single stage.

Volume is the overall loudness of the sound waves put out by the speakers. In an amp, the Volume control is used to attenuate the gain in any stage of the amplifier. This is usually done by means of a variable resistor (i.e., a potentiometer) shunting part or all of the signal to ground. An amp that has a Gain control can make a clean signal louder or quieter or, conversely, a distorted signal louder or quieter.

Q13: I recently bought a Plush amp without its tubes. What types of tubes does this amp use and where do they go in the amp's tube sockets?

A:  This is going to need more work to be accurate.  I have found that the tube lineup changed for the same model over the run of the amps. Not much consistency here.











To be continued...





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