A Buyers Guide To Valco Amps

Questions and Answers with David Wilson of the ToneQuest Report and Terry Dobbs a.k.a. “Mr Valco”

In your opinion, what are some of the most desirable Valco amps and why?

1000x1000Valco made many different amps over a period of many years, and the circuits continued to evolve as time went on, so there are a lot of cool amps to consider. If you also include the National Dobro Corp. amps made before the Valco Manufacturing Co. was formed after WWII, the list would certainly be a long one, but here’s an overview of five that represent a cross-section of lower and higher power amps:

Supro1605 Reverb Made in the early 1960’s, combo amp with 1-10” Jensen C-10-R, 12AX7, 6DR7, 6EU7, 2-6973 output tubes and 5U4 rectifier tube, volume, tone and reverb on/off intensity switch. This is a somewhat rare amp and there’s a Gretsch Electromatic version of the same. This is very loud for it’s size, and in fact, has the same power chassis as the early Gretsch 6162 with 2-10” speakers, and has a rich tone with major gain and overdrive. The reverb isn’t all that great sounding, probably a notch above the old Danelectro amps, but the intensity control circuit has a cool and probably unintended characteristic… as you turn the reverb control down, the gain goes up, and in effect, the intensity control can be used as a master overdrive control, and you can dial in the amount of gain you like. This is because the circuit takes some of the dry signal off the volume control to drive the reverb circuit. The reverb sounds pretty acceptable if you just blend it in enough to hear it, but fine tuning the intensity control is the key and puts the already great sounding amp over the top. A versatile and fine little amp that is one of the best sounding Valco’s I’ve owned so far.

1953 National Tweed There’s no model # on the amp, and it’s a very rare and progressive amp for it’s time. I’m sure it was the top of the line Valco made in 1953. Just a huge tweed amp with 2-12” P-12-P’s, 2-6SJ7 pre-amp tubes, 2-6SN7’s, 2-6L6’s and a 5V4 rectifier and 6SL7 tube used for the treble and bass circuits.. It has active tone circuits in it! The active tone circuits in the National dedicate a triode from each half of the 6SL7 to amplify the treble and bass frequencies rather than employ a passive cut circuit commonly found in most all guitar amps. The control panel is a cool light-up etched Plexiglas and the chrome handle is very large. It’s such a high gain amp that tube selection is critical to avoid any microphonic problems. This same chassis was also used in another National amp from the late 50’s that featured 1-12” Jenson P-12-n speaker. These are the only two Valco amps I have ever come across that have active tone circuits, a rare thing to find in any guitar amp.

oahu1National Glenwood Model 90 Made in the early 1960’s this has 2-12” C-12-PS speakers, 2-6L6’s, 5U4, 12AU7, 3-6EU7’s and 12AX7. Two channels, tremolo and reverb and a 3-way switch for hi-bass, lo-bass and guitar for each channel’s nputs. Another scarce amp and a very fine “bluesy” amp to play. Features a very nice transformer driven large pan reverb, rich deep tremolo, and 25-30 watts of output – great for medium sized clubs. Boost pedals work well with this amp and it’s well suited for a variety of styles of music. Very good tone and reverb – just a fine all around amplifier Supro

1600R Supreme Made in the early 60’s, this amp has 1-10” Jensen C-10-R, 2-12AX7’ s, 2-6973’s and a 5Y3. Volume, tone controls, two regular and one treble input. There were many versions of the Supreme amp thru the years, starting with the 6J7 preamp tube model with a 10” field coil Rola and single volume control, thru the 50’s going with the 6SQ7 preamp tube and 3 inputs volume and tone control, then a transitional amp in the mid-50’s featuring a combination of 9-pin miniature and octal pre-amp tubes, then the 1600, 1600B, 1600R, 1600S and the 6400. Starting with the 1600 series, the Supreme went from the 6V6 to 6973 output tubes and this version is a surprisingly loud little tone monster with the signature 6973 output tube crunch. For backroom jamming, recording or practice, it is certainly an amp worth acquiring.

Montgomery Ward Airline Model 62-GVC9037A This is one of Valco’s highest power guitar amps, and also one of the coolest funky-looking jobs they ever offered. Mine was manufactured in 1966 and represents one of the very last models Valco made that still included tube rectification. Came with 4-6L6’s, 2-5U4’s, 5-12AX7’s and a 6DR7 reverb driver tube. 2 Jensen 12” C-12-PS speakers, volume and tone controls for both channels, 3 inputs per channel (one treble and two regular), reverb intensity, tremolo speed and intensity controls. This is a serious guitar amp, with plenty of volume, tone and headroom to play out in most any medium to large clubs, and has a very good sounding tremolo and nice deep reverb. With the huge power transformer and the 2 extra beefy output transformers, this model could seriously compete with the big boys. Although the funky wood grain covering material looks a bit cheesy, the astigmatistic swirly grill more than makes up for it in the cool factor department. For an amp made in 1966, it ushered in the late 60’s psychedelic era a bit ahead of it’s time, and in my opinion was about the pinnacle of Valco’s circuit evolution as well.

For someone considering acquiring a Valco amp (or amps), what are the most important factors to consider – ranked by their importance? (Cosmetic condition, originality of various components, speaker, modifications, etc.)

gretsch-carousel_bkOriginality of the circuit is important, especially on the later model Valco’s from the late 50’s thru the 60’s. Some are fairly complex, and any “misunderstanding” or “hack job repairs” can hurt the tone of the amp and be expensive to put back to stock.

Look at the transformers, chassis, metal parts of the amp… it can tell you what kind of storage conditions it’s been thru. If you see a lot of rust on metal components, mold or mildew on the cabinet or output transformer, you can assume it’s been in a moist or humid environment and that could affect the service life of critical components. Check the cabinet for cracks, loose joints, etc. Some early Valco’s used 3/8” plywood for cabinet material and some have held up better than others over the years.

Although there are a lot of good aftermarket transformers available today, original transformers are always a welcome discovery and insure that when properly serviced the signature sound of the amp can be achieved.

For collectors, cosmetics and original components, speakers, etc., are things that affect the value of the amp. For players looking for a great sounding amp, the speakers and to a degree transformers need not be a “make or break” deal. Mercury Magnetics makes some replacement transformers for Valco’s now, and there is a wide range of fine speaker replacements available, so let your ears be your guide if you’re a player more than a collector.
Don’t worry too much if an old Valco has a bit of a hum, low volume, non-working tremolo, etc….if you’re acquiring it at a cost that you can get it serviced and still be within your desired price point after it’s serviced.

Are there any internal components that determine/effect the sound of these amps in particular the presence of which should be “deal breakers”? (If they’ve been replaced…. Walk!)

Many of the 1940’s and early 50’s amps used 4 ohm speakers, including the early Supreme’ s, Comet and Spectators. Most of these had the output transformer mounted on the speaker frame with rivets. I’ve come across a lot of these amps that had the speaker and output transformers both replaced and using 8 ohm speakers and those poor sounding universal output transformer to boot…. This really degrades the volume and tone of the amp! If you have played any of those amps sounding the way they are supposed to, you wouldn’t want to spend a lot on one of the smaller early models that have been repaired in this way.

641Valco’s used many “obsolete” octal tubes. Are they still available as new old stock (NOS) or current production? Can certain tubes be substituted with others with good results (or even an improvement in tone)?

There are current production octal preamp tubes out there now – Russian and China made stuff – I really don’t recommend them except as a last resort, or if you’re low on cash. You can still get most any NOS tube you need from “Antique Electronic Supply”, “Angela Instruments”, and many other reputable sources. 6J7 metal tubes used in the early Supreme amps can be microphonic in those amps and sometimes you need to try a handful to find a really good one. They’re fairly cheap still and you can also use a metal 6K7 as a drop in sub with little change in the tone or gain. The 6SJ7 can be replaced with a 6SK7 in a pinch as well. Valco used the 6X5 rectifier in some amps, and the 6AX5 is a good sub, and in fact, an upgrade. The hardest tube to find a NOS replacement for is the 9-pin, 6973 output tubes. They’re still available, but prices are getting way up there. There’s an over sea’s version available, but it’s sonically not up to spec with the NOS versions, but they are priced reasonable. Best bet is to have a good tech run a jumper wire between pins 1 and 8 on the 6973 sockets and then you can use either the 6973 or 6CZ5. The 6CZ5 is still priced reasonable, about $10 apiece at most tube vendors. Although the 6CZ5 is rated at a maximum voltage of 350 volts as opposed to the 6973 at 440 volts, it’s a good replacement in the lower voltage circuits Valco commonly used. I have found them to be reliable and sound every bit as good the the 6973’s.

What types of speakers were most commonly shipped in Valco amps? Can they be reconed with good results, and if not, what are your favorite replacements?

Valco used both Jensen and Rola speakers from early on until the 1960’s when they started using Jensen’s almost exclusively. They can all be reconed with good results if the work is done by someone competent and vintage correct components are used. It’s important to remember that any recone will require a break-in period before the speaker will open up and sound as good as it used to. Some reconers use kit parts that will never sound as good as the old speaker did, so stick with reputable reconers for best results and ask about the parts they use. WeberVST does a very good Jensen recone, and I also think their replacement speakers are fine upgrades.

In general, can you describe what you typically do when restoring an old neglected amp as part of your service to make it sound its best and operate reliably?

I open it up and inspect the amp looking for any obvious problems. Check to see if the correct fuse is installed and if the circuit is intact and appears stock. Then, test the tubes, put the correct speaker load on the amp and bring it up on a variac. Then I do some voltage readings in the power supply and other critical areas and test to find out if any coupling caps are leaking DC voltage. Then I verify all the resistors are within tolerance and not burnt or cracked, and check all ground connections. A “normal” servicing will include replacing filter caps, cathode bypass caps, drifted out of spec resistors, leaky coupling caps, cleaning, and retentioning tube sockets, installing a 3-prong AC cord and removing the “death cap” circuitry for safety. Also all grounds are properly established, jacks and pots are tight and cleaned, and transformers are tight and secure, circuit wires are routed correctly, no cold solder joints, etc. I use vintage correct parts where ever possible. Once the circuit is serviced, I fire it up – checking the voltages again and plug in a guitar and play… checking the speaker and all functions. Sometimes I will put the amp on a scope if I have any suspicion there are any oscillation problems. When properly service, the amp should be nice and quiet when nothing is plugged in, have good volume and tone, all functions and controls operate correctly and smoothly, and be good for years of reliable service.

If you could own and play only one Valco, what would it be?

That’s a tough call to make, since I have way too many amps already and too many “favorites”… but it would be the Supro1605 reverb… hands down.

What is your recommendation for the best model for a novice Valco owner to buy as a starter?

Valco’s from the late 1950’s typically require less servicing than the earlier amps do, and often still sound great even though in complete stock condition. This is because they got away from using the wax dipped paper coupling caps that have a very high leakage rate and started using ceramic disc caps that seldom, if ever, fail. The lower voltage circuits Valco typically used puts way less wear and tear on the old filter caps. Most later model Valco’s have a unique signature voicing that separates them from the other amps. If you can find a later model 1606, Supreme, Spectator or Comet amp for a decent price you’ll get the general idea of what the Valco tone is all about. Look for the off-brand Valco amps that are the same circuits but don’t have the Supro logo – they’ll typically go for less. Avoid the 1611S Bantam model unless you like amps with no power transformer and the potential to shock the crap out of you or worse. Any Valco that is in decent working order and is at a reasonable price point because the seller hasn’t mentioned the name “Jimmy” would be a great start!

Visit the ToneQuest Report