Sano/Gretsch amp on eBay

littlesongs said:

Thanks John. I am gonna have to pick your brain about Sano amps sometime.

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Hi Lilttlesongs; not sure I have much to offer but we have another BBer who knows Sano amps and has nice things to say about them. This is a Sano-made, Gretsch-branded reverb/tremolo amp on eBay now. Two channels, standby and polarity switches and hum balance on the chassis.




Busy place back here ... the seller garbled the auction text ... says he thinks it's 35 watts ... later it's 30 watts and bungled the power tube ID; they look like 8417s but the text also mentions EL34s and, for confusion's sake, an EL84. I think it's 62-65 or so mostly because of the handle and about when 8417 came and went ... if that's what they are ... could be EL34s ... no thanks to the seller. I guess the amp-to-the-left is the original layout but the power transformer is on the same side as the 15" speaker ... all the weight on one side ... unless you are Pop-eye, would be awkward to carry. Huge output transformer on the right end of the lower chassis ... about the same size as the ones in the 50W Guild heads.




View of the control panel; in reasonably good condition:




The webkeeper of the Sano flame is Larry John Macnally his webpage here including some discussion, list of models, and a few linked schematic; I didn't find a link for the auction amp. Some more discussion of Sano Amps at Ludlow Guitars, a link to a very interesting Sano Flicker show here, and a Craigslisted Sano in Washington state here.

The discussion in the links frequently mentions the hi-fi orientation of these amps; the seller mentions the auxiliary stereo channel, the fact that the speakers are crossed over shunting the high frequency signal to the small speaker and the mids/lows to the 15" speaker, and I think it's interesting that the OT is so large considering that the amp has a tube rectifier.

Do you have a Sano or thinking about buying one?

John

Are you sure that's a Sano John? I thought most if not all Gretsch amps were Valco made?

Hi Walter; so did I. If you click the Larry John Macnally link and go about 1/2-way down ... on the left side there's a pic of a Sano with the same unusual layout; not just that the preamp is up and power amp down, it's the unusual forward-facing preamp tubes ... they project into the top of the cabinet instead of hanging upside down; clears the interference between the speaker and the tubes but puts the tube heat in an unventilated area ... maybe there's vents I missed though.

Unfortunately the Craigslist link I posted has gone dead but it had a Sano that had the same silk-screen 'chevron' and other details similar or matching the auction amp. Finally if the speakers really are crossed over as the seller says, that's a hi-fi touch that I don't remember seeing on any other Gretsch/Valco 2X amp. Our BBer Valcotone knows his Valcos ... he might not be able to say whether it's a Sano but he might be able to rule out Valco.

Found another Sano amp Here on eBay It's clearly a Sano but looks like a Gretsch. Seller says: "... 1X15" gold Utah speaker & 1X10" Green Utah speaker." but later in the text says the smaller speaker is a "... UTAH 8"GM8J ..." 50 watts, stereo in and tape out jacks rare for a conventional guitar amp, 5AR4 rectifier, 6CA7/EL34 output tubes, 6J5, 6SN7 and 6SL7 but two tubes missing:




Note forward-facing tubes in preamp chassis like original auction amp, small box fastened to middle of baffle ... a cross-over blocking the low frequency signal from bogging down the 8" (10"?) speaker and the chassis pushed to the right to balance out the weight of the larger speaker magnet. That's a monster OT on the right ... :shock:

I think the first amp above is a Sano that somebody put a Gretsch logo onto (in a funny position), and possibly re-covered. I would not take this alone as evidence of a Gretsch-Sano relationship.

teleharmonium said:

I think the first amp above is a Sano that somebody put a Gretsch logo onto (in a funny position), and possibly re-covered. I would not take this alone as evidence of a Gretsch-Sano relationship.

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Hi Mark; agree ... I think the first amp is a Sano too with its horizontal preamp tubes ... I asked the Sano-Gretsch question over on Valcotone's Valco BB Link Here. I hadn't considered a re-cover but that makes sense.

littlesongs said:

'66 Sano 25WR ... plug in my F-212 ... holes in top ... I am reluctant to spiel, but I think Sanos are truly the last great bargain in vintage tube amplifiers. Were they ignored forever because of the stigma of polka? Or is the hard to find tubes that are priced really high for the high rolling audiophiles? Maybe everybody thought they were Japanese? :lol:

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Hi Dave; I could see how there would be a lot of heat buildup in the top of the cabinet with the preamp tubes oriented the way they are .. spieling is ok here ... it's done every day! The Sanos get dissed as R&R amps as 'too stereo' ... I hadn't thought about them for acoustic though; they were built to suppress distortion. Interesting amp; tremolo and reverb, 7591s out and a 5Y3 rectifier.

With one exception, all the tubes on the schematic are still in production including the 7591 that ElectroHarmonix brought back a few years ago; the exception is the 7199 ... going the way of the 7027, 8417, and a few others - Sovtek 're-issued' the 7199 but a lot of people prefer the more expensive NOSs that are still around or the RCA used ones. Very unusual reverb scheme; in a typical combo amp, 1/2 of one tube is connected directly to the reverb transformer and can and another tube 1/2 recovers the wet signal, amplifies it, and sends it back to the line.

In this amp, the to-be-'verbed signal arrives at the front triode 1/2 of the 7199, is amplified, and then connected to the back pentode 1/2 of the 7199 and then connected to the reverb transformer and can with a capacitor. The wet signal goes to 1/2 of a 12AX7 where it's amplified and then to the other half of the same 12AX7 and then back to the line. That's twice as much signal gain ahead of the transformer/can and twice as much signal gain after the can as standard guitar amp layouts ... :shock: A lot of engineering ... you have either a killer or clunker reverb.

It has a stereo/'Y'-in jack; L and R each get one gain stage and the signals are mixed just ahead of the tone controls to accommodate accordion electronics with a channel for each hand. Another BBer has nice things to say about Sano amps; Interesting application with an F212 (one of finest guitars ever made :wink: ) looking forward to some pics. John

There are a lot of BB posts elsewhere about how to slow down older trem oscillators; the physics are past me but I'll look around ... see if I can find some discussion. I believe it's a matter of changing the values of either/both the resistors and capacitors in the trem circuit (halving or doubling ... can't remember which)... 3 capacitors and 2 (or 3?) resistors; takes more time to locate them than it does to take them out and replace them. In the second of the two amps above, I think that crossover is a slick piece ... lets the small speaker see only the high frequencies; gets the speakers into woofer/tweeter relationship .... Ampegish makes sense.

Yes; that's quite a speller boner ... :shock: :shock: :wink:

Hi Dave; that's a serious handle on there too :shock:

This is the 25WR schematic marked up to show the 'stereo-in' jack on the left. With the extra hot post, it's looking for a stereo plug w/ 2 hot legs and a ground. It feeds the channel 1 and 2 preamps and then the signal goes through separate vol controls and then mushed together. The reverb circuit is also shown in blue with arrows indicating direction of signal travel; where the line is tapped feeding the twin stages of the 7199, the reverb can, recovery by twin stages of a 12AX7, and the wet signal being returned and mixed with the dry signal at the front half of the 12AU7:




I messed up above; started looking at similar reverb designs and the 25WR, like the Princeton Reverb and Gibson GA30RV, uses two gain stages ahead of the reverb can (red dotted lines - I said one) but, unlike Fender, Gibson, and Ampeg, the Sano uses two gain stages after the reverb can (blue dotted lines). Both Fender and Gibson used transformers drive the reverb can and match impedance (green boxes). Gain stage tube sections commonly have 2.5K or so internal impedance and the more common reverb cans have as little as 8 ohms although they can be made with 2.5K impedance as well. Ampeg used a .47uf capacitor (magenta box) to couple the reverb can (2.5K input impedance) to the driving stage, block DC, and block higher frequency signal. The Sano drawing is a little ambiguous; it doesn't look like there's a transformer there (got one somewhere on the chassis?). If not, then the driving stage is coupled to the reverb can with a .05 capacitor (allowing more high frequency through) and blocking DC.




So ... the Sano reverb is like Fender and Gibson with two gain stages ahead of the reverb can, like Ampeg in coupling the can with a capacitor, and unlike anybody in using two gain stages to recover the signal. Assuming the Fender/Ampeg/Gibson designs work fine with only a single recovery stage - and speaking for the GA30RV ... it does work just fine - , then it's possible that the Sano designers wound up with an unspoken-for tube 1/2 and decided to use it for no other reason that it happened to be there. Ampeg reverb used one section of the odd-ball 6U10 - a three-section triode ... exactly like a twin triode 12A_7 except with one more triode section in the same bottle - to get around the problem of having an unused tube half otherwise go unused.

You have me thinking about Sanos as tube amps for acoustic guitars; that pickup in your F212 (it's a beauty too!) ... it looks like an old DeArmond? John

Speaking of Sano reverb ... the unidentified Sano in this closed eBay auction used speaker-coupled reverb like Guild's Thunder 1 RVT and version 1 Thunderbird. Utah? speaker-mounted capacitor feeding 9 inch (4 spring?) reverb can:



J

Yowsa cj!

Default said:

Yowsa cj!

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I think Santa might be bringing a reverb amp to my house for xmas ... <smiley for hope so goes here> J

That would be cool. A little amplified 12 string surf, maybe?

Default said:

That would be cool. A little amplified 12 string surf, maybe?

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I think I'm headed for a split definitive .... I'd really like another reverb amp but I'd also like to amplify the 12-string. I guess I'm looking for the $hortcut here; our acoustic players use ss amps because they work well. A p/u for the F212 to drive a ss amp installed costs as much as a ss amp itself .... or a non-working 'hi-fi' Sano ... which, of course, would leave the problem of a reverb amp. :?

littlesongs said:

... it seems like accordion players wanted reverb with a faster attack and much shorter decay time ... so they could hit it hard and chop off the tails. It makes a fair amount of sense for the dynamics of the instrument. Yes; playing 'Stairway to Heaven' on the accordion with extended decay ... that's just no good ... :wink: I have read about folks jumpering the channels and whatnot to get more dirt.. 'Daisy-chaining' ... will increase gain but you could say goodbye to the clean thing ... My songs are "baroque-a-billy" -- in other words, I play guitar kinda like a piano and the arrangements have many different chord changes. I listened to some of your work ... 'baroque-a-billy indeed interesting stuff! Maybe Santa will get the hint.

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As I suggested earlier, the cost of high-grade modern p/u in the F212 is about the same as the cost of decent used Marshall or Fender ss amp intended for acoustic use so this will get down to which 'solution' appears first; a 'tweedish' reverb amp or a 'Sanoish' reverb amp. Next time you take the back panel off, consider snapping and posting a few gut shots. I looked up your Oregon island ... charming place. J

Hi LS: saw your memory magic trick in the other thread ... sometimes I have a hard time remembering what I had for breakfast :wink: Would love to see the Sano's interior but have to say that my case of Sano-itis may have run its course. I had gotten a little pumped up by looking at back-to-back-to-back Sano listings on eBay. I used to complain that there was so many more interesting rigs up your way than down here ... and still do ... very few Sano / Magnatones / Hilgens in So FL from back in the day adding some risk to messing on eBay with 'spec' amps but if you think about, the pics would be pretty interesting. Best, John

littlesongs said:

... Forgive me for saying so, but I thought that Florida would be bursting with accordion amplifiers. At the risk of racial profiling, let me just say that I was under the impression that many retirees have deep roots in traditional squeezebox nations.

Hi littlesongs: Well ... you'd think ... my guess is that a lot of accordion hobbyists, when arguing about what to leave in and what to leave out when departing for Florida were confronted with something like this:

He: 'There'll be plenty of room on the truck for my acco and amp'
She: 'Why are bothering; you don't play it very often or very well as it is'
He: 'Wanna tell me again why I married you?'

Besides, they all live in condos; there's no place to play even at moderate volumes.

Control panel, retrofitted heat vents, and coincidentally the exact same handle as an Echoplex. Given the forward-facing tube orientation, good to get some ventilation ... more than one Gibson amp had their OTs fail/melt down because of trapped heat. New reverb tank, original 12" speakers and overhauled circuitry underneath the chassis. Orange Drops all around. A proud New Jersey native along with Ampeg, Hilgen, and of course, Guild!

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Thanks again for the pics; the BB can use all the amp porn it can get! John

Hi littlesongs; I like the 90 deg wiring in the Sano amps; easier to follow what's going on .... this one ... there's a 160R schematic out there; same as this one except with reverb. That un-used socket on the tube deck got filled with a 6SC7 and one 1/2 of one of the two 12AX7s would have been hooked up in the reverb model.

Larger output transformer than a similar Gibson EL84 amp from a few years earlier. SS rectifier but schematic doesn't show a standby switch. In a ss amp, current flows through the output tubes as soon as the amp is turned on; that is, electrons are being stripped off the cathode before the filament has heated up. The lack of a standby switch can deaden tone and shorten useful tube life faster than in an amp with a standby switch.