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Mono Mania

A Review of the Sweet Foot Pedals Outboard Stereo-Mono Switch

[Italian version here]

Product name:Sweet Foot Pedals Outboard Stereo-Mono Switch
Manufacturer: Sweet Foot Pedals - USA
Cost: $30 (with free shipping) (Currency conversion)
Reviewer: David Hoehl - TNT USA
Reviewed: May, 2021

Regular readers of my scribblings will know that I constantly preach the gospel of “be sure your gear will play in mono if you are venturing into vintage records”; for instance, see here (where I discussed the different types of mono modulation--we'll have more on that subject shortly) and here (where I offered suggestions for setting up a basic 78 RPM system). Here's the problem, though: mono switches are not especially common features of latter-day gear, and more often than not those of us who wish to get started with 78s, or even those who just want to explore LPs from the period before stereo fully swept the boards, already have satisfying or even top-notch stereo-only equipment that they are unable or unwilling to replace.

The Warm-Up Act

As a starter, here's an example of the improvement possible just by switching from stereo to mono when playing 78s. The record is a 1940s-vintage American Decca pressing of Frankie Carle in a number from a musical generation earlier, Zez Confrey's evergreen piano dazzler “Kitten on the Keys.” It's just the sort of record one might expect to turn up at a flea market or garage sale--a passable but not top-notch pressing in about average, or maybe a little better than average, condition, neither especially quiet nor especially noisy. The buttons immediately below will let you hear the first couple of phrases in stereo and, for comparison, in mono; if you want to end a sample early, press the one labeled “stop.” I applied no noise reduction or other processing to these samples beyond placing them in a single file to normalize them to the same level. Note, however, that had I been normalizing only the mono copy, without the stereo copy's extra noise, I could have raised its level considerably.

Good Things Come in Small Packages

So, what do you do if you want to get the benefits of mono playback but your gear lacks a built-in mono setting? Good news, folks! Now, thanks to a supplier with the unlikely name Sweet Foot Pedals, adding a mono setting to existing gear is easy and inexpensive, a good (albeit, as we shall see, not quite perfect) solution to the dilemma.

As you might guess, Sweet Foot Pedals seems to cater primarily to the electric guitar crowd. For whatever reason, however, it carries several nice little add-on boxes for the audio hobbyist, too. Besides the mono switch under review, its offerings include various hubs to intermediate between mono and stereo, all in similar nicely finished little metal cases. I do mean little; these things have a smaller footprint than a cassette tape, although they are a little thicker than the cassette box. In addition to the standard turquoise, they can be had with a plain aluminum finish or, at a $1 extra charge, in cream, black, red, or--bubblegum pink! All seem to have the same distinctive, amusing artwork. The company indicates they are all hand-assembled in the United States.

The device's physical layout is straightforward: two pairs of RCA jacks on the back, a single miniature switch on the front to select mono (when set to the left) or stereo (when set to the right). The switch looks like a conventional device of the sort one could have bought at any Radio Shack store in years past, nothing “special” but perfectly acceptable for its intended purpose. The jacks appear to be similarly of good, routine quality, and according to the company, the jack pairs are not directional; you can treat the first set as “in” and the second as “out” or vice-versa without concern as long as you keep left and right consistent. The case is a sturdy metal box, nicely finished with rounded corners and edges.

As noted below, I did find that the jacks have a slightly smaller diameter than those on some of my other gear; the plugs on some of my cables didn't give a snug fit. The case paint of my sample shows faint circular grooves around the jacks, presumably evidence of a socket wrench that tightened them in position. I found that hint of human hands assembling the unit to be part of its charm.

In Action

That's enough of form. What of function? With a device like this, either it works, or it doesn't. Simple, right? Well, turns out, it's not--in the case of the Sweet Foot Pedals mono box, it does, and it doesn't.

Those who have read my rambling articles in the past, or who were brave enough to check out the earlier article linked at the beginning of this one, will recall that historically mono records have come in two flavors: lateral cut and vertical cut. Briefly, for those new to the subject, lateral cut is what everyone today calls “mono”: the groove is cut at a constant depth and modulated horizontally, causing the stylus to swing from side to side. Lateral cut is the groove type for all mono LPs and the general run of what most people call “78s” (everything after around 1930 and the common brands like Victor, Columbia, and HMV before that). During the acoustic era, however, certain labels cut a groove of constant width but modulated vertically, causing the stylus to bob up and down--hence “vertical cut” (or, more colorfully, “hill and dale”). This type of groove is found in all cylinders and in disks by Edison; Pathe; occasionally Brunswick and Vocalion; and at least sometimes such small labels as Rishell, Lyric, Rex, OKeh, Gennett, and on and on.

In either case, the record has signal in one plane and nothing but noise in the other; accordingly, you'll want to desensitize your system to the latter with a mono switch like the one under review. With the exception of a few pieces of specialist gear incorporating a dedicated vertical cut option, a switch labeled “mono” will set the equipment for lateral cut, the winner in the great format shoot-out of the 19-teens and 20s. How, then, to play vertical cut without a lateral component? The standard method is to miswire a cartridge, swapping a ground and “hot” lead; this arrangement ordinarily will yield a pure vertical signal when summed to mono with a standard switch.

The Sweet Foot Pedals add-on box works perfectly for lateral cut records. Switch left, signal out is mono. Switch right, signal out is stereo. Done.

Curiously, however, it does not appear to yield a monaural vertical cut signal when paired with a cartridge rewired as described above. I tried plugging it into the signal path in the following positions: between the music server and the amp, monitoring a “tape out” signal that had passed through my USB audio interface; immediately after the phono preamp, before the interface; and immediately after the turntable, before the signal passed into the phono preamp. In no case did the outboard box yield a pure vertical signal when switched to “mono.” As to the reason, I have no idea; I've never had the rewired cartridge technique fail before, and the mono setting of my Graham Slee phono preamp behaved exactly as expected.

How serious is this issue? I won't pretend that it isn't a fault, but I also won't pretend that it's grievous for this component's typical audience. For one thing, you are unlikely to find vertical cut records without actively seeking them out; at least here in the United States, the overwhelming likelihood is that the records in those piles of old shellac at the local flea market or garage sale are from the big band era or later, when vertical cut had disappeared from the market, and if they happen to be earlier they will probably be issues on lateral labels like Victor or Columbia. If you like Bessie Smith or Benny Goodman or Les Paul (or Vladimir Horowitz or Jascha Heifetz, for that matter), you'll be collecting lateral cut records. For another, although it's not an iron-clad rule, artists tended to appear primarily in one format or the other, and the ones who recorded on vertical cut records tend not to be the ones of interest to non-specialist collectors today. To cite my favorite example, Enrico Caruso made only three vertical cut records, all early in his career, and he remade two of those selections for Victor in lateral cut later on. Doubtless in part because his records were in the format that prevailed, everyone knows the name Caruso, and they remain popular today. Ever hear of Albert Vaguet? Unless you're a “serious” collector of 78s, probably not, even though he was a significant tenor in his day and made at least as many records. His, however, were vertical cut recordings on Pathe, and after the late 1920s they were effectively unplayable for decades. Therefore, I think it's safe to say that collectors who have vertical cut records are likely already to have gear that will handle them without needing to add on something like the Sweet Foot Pedals mono switch box. Just bear in mind that if you do want to explore vertical cut records, this device probably won't be of much help.

Some Examples

Now, I can already hear the “having a paper with 'tone controls' written on it in the same room with your amp will degrade the sound” contingent starting to sharpen pikes and break out the pitchforks, convinced that deviating from “nothing in the signal path but wire, cryogenically treated on Neptune” will instantly transmute audio gold standard Bryston into (shudder!) audio fool's gold Bose. Yamaha into Yorxx. Naim into no-Naim.

Uh, sorry about that. “As well you should be,” quoth a disgusted member of the contingent. Slinking onward, I continue: I did experiment a bit to establish whether I could hear the box in any way degrading the sound, and I never detected any hint of trouble. I'll freely admit, though, these antiquarian (and antiquated) ears may not be the most authoritative of judges. Therefore, I'm including three brief recorded examples from which you can draw your own conclusions, be they only that the author should stick to Victrolas.

All the samples are from LP records copied to computer with the gear listed at the end of the article. My apologies that the third shows some hints of wear; I bought it used. In each example, one channel goes straight to my recording computer's outboard USB audio interface from my phono preamp, and the other passes to the interface thorugh the Sweet Foot Pedals switch box, which I left set to stereo even though only one channel had input. If the box degrades the sound in any way, you should be able to hear it by direct comparison of the two channels. (I will note in passing that the test is not perfect, as posting to the Web requires conversion of .wav files to .mp3; to minimize ill effects, I set my conversion software to the highest bitrate of which it is capable, 320 Kbps.)

The first sample is part of a serenade by Biber, pizzicato strings accompanying a bass soloist (in German). The record is a DMM LP from the 1982. Hans Stadlmair leads the Munich Chamber Orchestra with bass soloist Kurt Moll, who sings the following:

Lost Ihr Herrn Undt last euch sagn
Der Hammer der hat neyne gschlagn,
Hets Feyer, hets wohl,
Undt lobet Gott den Herrn,
Undt unsre liebe Frau.

A rough translation would be as follows:

Hear me, good people,
the bell has rung nine o'clock.
Settle down and dutifully tend your fire,
And praise our Lord
And our beloved Lady.

The second example is the opening of “Mars, the Bringer of War” from Holst's The Planets, but with a difference. Holst composed his famous suite by first working it out for two pianos (except for the Neptune movement, which he first set for organ), then orchestrating it. This approach was by no means unique; Stravinsky, for example, composed The Rite of Spring in the same way. The two-piano sketch had a private performance or two before orchestration was complete, but for the public the seven movements were always orchestral works, as Holst had intended from the beginning. The two-piano score was not lost, however, and in 1981 the Delos label released a recording of it by Richard Rodney Bennett and Susan Bradshaw on LP, the form in which I have it and in which it is heard here. Later, it made the transition to CD.

This article is not the place for a detailed review of the recording, but I will add a few words for the benefit of the curious. Taken as a whole, as you'd probably expect, the work loses a lot when denuded of its colorful orchestration. That said, the two-piano format does work surprisingly well in some movements, and I'd say “Mars” is the best, perhaps the one case in which the prototype can stand comparison to the finished product. If the orchestration undeniably has more color, the pianos offer us their own brand of sharp rhythmic pointing and sonority highly suited to the character of this ferocious music. In some of the quieter movements, on the other hand, they seem simply bald, and in “Neptune” they are quite helpless to stand in for the wordless women's choir.

The third example is an excerpt from the last movement of Weber's first piano sonata performed by Beveridge Webster. Under the title "perpetuum mobile," the music, extracted from the larger work, at one time was something of a favorite encore piece. American pianist Webster, a close friend and associate of Igor Stravinsky, had a significant career in the middle of the 20th century both as performer and teacher, first at the New England Conservatory and then at Juilliard. He might be better remembered today had his record not nearly all been on the defunct Dover label, of which this one is an example. Unlike the two preceding records, which were issued in stereo, this one is in mono. I recorded it in stereo, however, to give one example in which the right and left channels should be essentially identical.

The buttons below are labeled with the record choices; click a button to hear the audio extract and click the “stop” button at any time to turn off the audio then playing.

I will offer one final example, not as a test of unintended audio consequences but rather as a demonstration of this little box's power to address an audio problem, which arose because I had violated my own advice, specifically that playback equipment for vintage recordings should always have a mono setting. My phono preamp, a Graham Slee Jazz Club, indeed does have a good one, but considering I expected to need the mono setting only in connection with records, for an amp I chose a Bel Canto model that offered the Tripath-based amplification I wanted but that is stereo only.

Well.

What I hadn't expected was that I would encounter a CD, of all things, that would call for playback with an amp set to mono. “And thereby hangs a tale.”

Hans Pfitzner is a name not especially well remembered today, at least in the English-speaking world, outside the ranks of music historians and collectors of old disks, but in the first few decades of the 20th century, up into World War II, this German composer was an important figure on the musical scene, and his compositions figured regularly in concert programs not only in Germany but across the world. He also was a pioneer conductor on records in the early days of electric recording, entrusted, among other things, with leading several Beethoven symphonies in one of the early attempts at getting them all on disk. (The idea of an integral set by a single conductor hadn't taken hold yet; the first conductor to be represented in all these works on record was Felix Weingartner, and his recordings spanned a couple of decades, with some duplications along the way.) Pfitzner's “greatest hit,” an opera called Palestrina, still gets performed in German-speaking countries, although it's hardly even in the fringes of the standard repertoire anywhere else. Among his other, now even less frequently played works is an imposing piano concerto given its premiere in Dresden in 1923. The soloist on that occasion was a major pianist of the day, Walter Gieseking, still remembered as an important exponent of Debussy, who proceeded to champion the piece for the rest of his life.^[1] Thus, for those of us who enjoy the piece, a surviving broadcast recording of Gieseking performing the work in 1943 with Albert Bittner and the Hamburg Philharmonic Orchestra is a valuable historical document, leaving aside that as far as I know only one other recording of the work has been issued by anyone else. I have both, and the Gieseking performance is my pick as the better argument for why this piece is worth knowing.

The Gieseking recording was once issued on LP, but for practical purposes it is available to current collectors only on a Music and Arts CD or from streaming sites that appear to take the same mastering as their source. Unfortunately, Music and Arts, usually reliable in such matters, falls on its metaphorical sword here: claims of "best possible sound" notwithstanding, it's in fake stereo. The M&A mastering turns the sound into a real mess, congested, murky, and unnatural. Usually, playing a fake stereo recording back in mono clears the worst of such damage--but up until now my equipment has been able to apply a mono setting only to the turntable's output, not to any other source.

Enter the Sweet Foot Pedals mono box. Having long since copied the CD to my computer “server,” I inserted the box into the input chain for the Bel Canto amp, set the switch to mono, and had a listen. Sure enough, all that blowsy pseudo-stereo disappeared. To be sure, the recorded source is never going to take any prizes for audiophile splendor, but now the performance emerged sounding like something recorded (fairly decently) in 1943 Germany. Mission accomplished!

Once again, having set forth my reactions, I leave it to you to form your own. The buttons below will let you sample the opening passage of this recording in both ersatz stereo and mono as rendered by the Sweet Foot Pedals box.

Complaints

Aside from noting the peculiar failure to yield a vertical cut mono signal, I have two minor quibbles. First, with its small size, even modest interconnects like mine tend to pull the box around and tip it over. If you buy and install one, you may want to consider putting a bit of adhesive on the bottom to hold it in place. The flip side of this issue, of course, is a virtue: the box takes up next to no space and can be positioned pretty much anywhere you find convenient. The second is about the input and output jacks. On my box, they may be just slightly undersized, because I found some of my cables wouldn't seat snugly; the best fit was with a pair that are a little too tight for a comfortable fit to the Graham Slee phono preamp. That issue, of course, may have more to do with my particular cables than with the box. Just be aware of it if yours tend to the loose side with typical jacks.

Conclusion

Sweet Foot Pedals has done the collector of old recordings a nice service by offering its add-on mono/stereo box at a modest price. Granted, given the issue about vertical cut, it's not a perfect solution, and granted, what it does would be an easy do-it-yourself project for those so inclined, but for those wishing to play by far the majority of 78s and any mono LPs, it's fully up to the job. Home-brew results most likely would lack the nice finish and compact size of the commercial product, and at the price I'm not sure building from scratch would save much scratch. If you plan to play 78s, mono LP, or (surprise!) fake stereo CDs and don't otherwise have mono playback capability, I strongly recommend this little product as a serious upgrade to your listening experience.