Reel To Reel - Create Cable for line output to RCA?

[Rob_Feature]

I just picked up an old reel to reel which is stereo. On the front it has a jack for "Ext Amp" which I'm guessing is a line out. The problem is it's a 1/4" jack (which I'm guessing is TRS since it's stereo?).

I'm assuming it's fairly common to create a custom cable that'll go from 1/4" -> RCA plugs, so I can plug it into modern gear. If so, any tips on how to wire that? Thanks in advance!

 

[OutlawSun]

I just picked up an old reel to reel which is stereo. On the front it has a jack for "Ext Amp" which I'm guessing is a line out. The problem is it's a 1/4" jack (which I'm guessing is TRS since it's stereo?).

I'm assuming it's fairly common to create a custom cable that'll go from 1/4" -> RCA plugs, so I can plug it into modern gear. If so, any tips on how to wire that? Thanks in advance!

You can get 1/4" phono to RCA cables or adapters fairly easily. Amazon or some place like Microcenter carries them.

 

[Rob_Feature]

Yeah, I guess I just thought they could be made pretty easily since I have quite a few cables/ends sitting around. Maybe I'll just buy em instead

Am I right in assuming this is a line level output and can easily be adapted to RCA? I ask because your use of the word 'phono' made me wonder if there's something going on with these that requires a phono style preamp?

 

[rojoknox]

Greetings from RojoLand!

What make and model is your R2R machine? If it's an older rig, that "Ext. Amp" jack may not necessarily be TRS; rather, it could be a jack for an external amp for *the right channel* while the deck uses its built-in amp for the left channel. Some Wollensak rigs had this setup. It all depends on what particular deck you are dealing with. You should check HiFi Engine for the owner's and/or service manuals.

If it is in fact a TRS 1/4" **phone** (not "phono") connector, it's trivial to make up or purchase a TRS-to-twin-RCA (left-and-right) adapter cord. Usually, the tip of the 1/4" plug is left channel and the ring is the right; shields go to the sleeve.

Take care,
—
J. E. Knox "The Victor Freak"

 

[Rob_Feature]

Greetings from RojoLand!

What make and model is your R2R machine? If it's an older rig, that "Ext. Amp" jack may not necessarily be TRS; rather, it could be a jack for an external amp for *the right channel* while the deck uses its built-in amp for the left channel. Some Wollensak rigs had this setup. It all depends on what particular deck you are dealing with. You should check HiFi Engine for the owner's and/or service manuals.

Thanks! It's a Silvertone 9074 model reel to reel. It's got a 1/4" jack on the front (as mentioned) and a single RCA style plug on the side of the unit (unlabeled, not sure what it is). Here's a couple pics!

 

[rojoknox]

Greetings from RojoLand!

Looking for any info online on this machine; not much out there. I do find one report of its tube complement, and this does *not* suggest a full stereo rig: 12AX7; 12AY7; two 12AU7s; 6V6; 6AX5 (rectifier). With only one 6V6 audio power amp tube, I think you've got a stereo-capable set (the lid does state "Stereophonic High Fidelity" inside) that requires a second amp and speaker to playback in stereo (likely why there is both an Ext. Amp and an Ext. Spkr jack). It's also possible it does not *record* stereo (this too is common to decks of this era). To be certain, I'd need to see the heads (a clear, closeup photo of them). That RCA jack with adjacent pot is unusual. I see no labeling on it.

This rig will require a complete recapping. There's a chance the schematic can be found glued to the inside of the cabinet. Sams Photofact index shows it as Folder 422-14 from 1958 (not a free download).

If this is indeed a 1958 set, "stereophonic" could even mean two-track rather than quarter-track stereo, which will be a whole 'nother kettle of fish. Again, have to see the heads.

Take care,
—
J. E. Knox "The Victor Freak"

 

[Rob_Feature]

Yeah, I actually wondered about the mono/stereo question...the 'stereophonic' on the lid confused me It plays tape in both directions...so, would it be a 1 direction stereo or a 2 direction mono player? I wasn't real sure (and also couldn't find much about it). I plan to open it up in the next couple days (and will get some pics of the heads). Thanks for helping try to shed some light on what I've got here. (I was a "you're an audio guy, I donno if it works, but here ya go" Christmas gift )

 

[rojoknox]

Greetings from RojoLand!

Looked up "Silvertone 9074" in the Nortronics replacement-head catalog. It lists a "2M" head with reference note "2-TR Stereo Play." There ya have it — the machine is a two-track rig that has stereo playback, records only in mono.

Take care,
—
J. E. Knox "The Victor Freak"

 

[rojoknox]

Greetings from RojoLand!

Chances are it uses the "stereo" right-channel head for reverse-direction mono playback. You're correct—single-direction stereo player, two-direction mono player, single-direction mono recorder.

You *can* find two-track stereo commercial pre-recorded tapes, but they are collectible and spendy (plus you'd have to dig 1950s pop, jazz or classical music; if there are any early rock-'n'-roll two-track tapes out there [Elvis comes to mind], they've likely been snatched up long ago by collectors). Your machine can't deal with the much more common quarter-track ("4-track") pre-recorded tapes. There are two-track tapes being produced now, but running usually at 15 IPS and mounted on (sometimes multiple) 10-1/2" reels that your rig can't support. With the old two-track stereo tapes, there were two kinds — "stacked" or "in-line" meaning the two tracks were in dead sync with each other (as you might expect), and the older "staggered" type designed to play on machines with individual heads set apart (or staggered) which have a 1-1/4" distance between the same point in time on the left and right channels. Your deck uses the stacked or in-line type. A two-track stereo tape has no "side B" since the two tracks take up (essentially) the entire tape width.

Decks like this were actually fairly versatile for their time, but are actually transitional in nature. True stereo recorders for the home were a year or two away (or extremely expensive, being professional-level machines).

Perhaps down the road, you might acquire something like a ReVox B77 Mk-II two-track deck (I have one of these) which can make stereo tapes that would play fine on your Silvertone.

Take care,
—
J. E. Knox "The Victor Freak"

 

[Rob_Feature]

All amazing info here, thanks!!! However...I'm totally bummed. I was hoping to be able to pickup some commercial tapes for this, so that's pretty disappointing. But...better to know now than after buying a tape! Thanks so much again, valuable info here to get me started.

 

[rojoknox]

Greetings from RojoLand!

If you do go hunting on the Dock-o'-the-'Bay for two-track reel tapes, BEWARE that there are some counterfeit and — ahem — "homemade" tapes being offered. You'll note that many come from places abroad (Moldova?!). Some of these auctions come right out and say they're from USSR or whatever. Some others are touted as being two-track but the boxes shown are clearly marked "4 Track," "4444," etc. I guess some sellers can't read. Also BEWARE of claims that a tape is a "studio master." Such tapes are often dubbed off CDs, or if you're lucky, a duplicate (i.e., dubbed, or even dub of a dub) "master" reel. The true studio masters are of course retained by record companies in vaults.

Genuine original two-track pre-recorded tapes are collectors' items priced accordingly. This, however, is in my opinion quite extreme:
https://www.ebay.com/itm/153296115409

Happy hunting!

Take care,
—
J. E. Knox "The Victor Freak"

 

[TR6man98]

Ah, Brubeck's two track!
I agree it is expensive but there was one auctioned on eBay when he died and, IIRC, it sold for over $2000!

 

[Rob_Feature]

Technically these 2 track units (and a good 2 track tape) will produce significantly better quality than the 4 track (heads/bandwidth is twice as wide per channel), but if I really can't buy any tapes it means it's not something I'll probably keep. It would be great for producing home audio because of the bigger bandwidth, but commercial use isn't really feasible for me. Great info though, I appreciate all the input rojoknox!