RCA plug for speaker jack on Fender amp

[Underwood]

My amp has an RCA jack to plug the speakers in. I did deoxit it and it seems to make good contact, but I was wondering if I should put a 1/4" input and plug on it. It seems so easy to pull this RCA out and fry my OT by accident. 1/4" better sound quality? I don't know, but it would be a better connection I think.

[kagliostro]

No differences on sound, may be a more stable machanical connection

but I would like to see where is placed the RCA connector before to be sure, the RCA gives a good electrical connection

a better stable connection will be a Speakon, but you have to see if it is worth to make changes



the RCA may be sufficient depending on the location where was installed

K

[sluckey]

Fender used a lot of RCA jacks for speakers in their combos prior to the blackface days.

[PRR]

I don't see how a 1/4" is any harder to yank-out than an RCA. In fact I have seen RCAs so stuck that I had to pry them out with the screwdriver.

Neither connector is at all "right" for high power low impedance use. The RCA was designed for the microWatts (nanoWatts?) out of a TV tuner, or maybe similar levels out of a phonograph needle. The 1/4" is a cheap copy of the telephone operator plug, 1 milliWatt in 600 Ohms. Also a 1/4" jack on the speaker end will short-out the amplifier when it is yanked out. (You small-medium tube guys can stand shorts; early transistor amps would take early-retirement if shorted.)

The SpeakOn connector was *designed* for speaker work, but there is no chance it will catch-on in guitar land.

[eleventeen]

Agree that a 1/4" jack is almost comical for a speaker connector. Despite the obvious fact there are kazillions of them out there, they are really quite wrong for the application. An XLR would be a reasonable alternative up to medium power (hello, Ampeg B-15N?) but you sure have to bore out a giant hole in your chassis to use them, esp the females. 1/4" gets better with a right angle configuration. 


I don't think anything much gets accomplished with a connector jihad on an internal speaker connection. Neither of the common alternatives are very right.

[supro66]

Back in the old days 1960's
my 1965 Supro 6420 Thunderbolt has this type of speaker plug

[kagliostro]

Years ago the standard for HiFi (and not) was 2 Pin Din speaker connector








K

[sluckey]

Years ago the standard for HiFi (and not) was 2 Pin Din speaker connector

Maybe in your world... Not in mine.

[kagliostro]

Maybe in your world... Not in mine.

I don't know what you were using in the 60-70 era

here





Franco

[supro66]

There is always that British connection BNC

[sluckey]

There is always that British connection BNC

That ain't a British connector! And it does not make a good speaker connector either.

"The connector was named the BNC (for Bayonet Neill–Concelman) after its bayonet mount locking mechanism and its inventors, Paul Neill and Carl Concelman.[1] Neill worked at Bell Labs and also invented the N connector; Concelman worked at Amphenol and also invented the C connector. A backronym has been mistakenly applied to it: British Naval Connector.

The basis for the development of the BNC connector was largely the work of Octavio M. Salati, a graduate of the Moore School of Electrical Engineering of the University of Pennsylvania. In 1945, while working at Hazeltine Electronics Corporation, he filed a patent for a connector for coaxial cables that would minimize wave reflection/loss. The patent was granted in 1951."

[supro66]

A backronym has been mistakenly applied to it: British Naval Connector.


Boy I guess you are going to tell me
Philadelphia Cream Cheese aint made in Philly 

[kagliostro]

Oh, this will give you, for sure, a better connection



The PL259 is planned for RG8 cable but you can use an RG58 adapter



but I think it will be a bit oversized  


K

[eleventeen]

Just one of those situation where you kind of have to look past the shortcomings and make a down and dirty choice for the cheap and widely available 1/4" plugs. Inside a combo amp I can't see getting too excited about it.


PL-259 is ridiculous, a very awkward connector that makes no sense unless you use RG-8 cable, really fat ~~1/2" thick cable, very non-flexible. A BNC connector is also sort of silly but I could at least see the argument in favor. Of course you cant make them without a crimper. If you can get some high-quality (not Chinese molded-end) BNC cables with RG-58 cable (NOT RG-59 with a steel center conductor w/only a thin copper coating) at a military surplus place or ham flea market, OK. It's not any kind of 100-watt connector.

[mresistor]

If your gonna use lamp cord or 16 gauge wire then I would think the common two prong plug for a wall outlet would be best. I like that European style two prong connection like the one in Supro's post.  Heavy gauge wire on a 1/4" phone plug works for me.

[mresistor]

Sluckey, Fender also used rca jacks in the blackface and silverface era.  At least that's what my Champs are showing me.

[sluckey]

A backronym has been mistakenly applied to it: British Naval Connector.


Boy I guess you are going to tell me
Philadelphia Cream Cheese aint made in Philly 

I learned a new word today. Never heard of backronym before.

I'm not messing with Philly Cream Cheese. I am too fond of it, especially on jalapeño pepper poppers.

But I've used way more BNC connectors than I'll ever use phone plugs, or RCA phono plugs, or any other connector for that matter. But BNC is great for it's intended use, but it is pricey and a poor choice for a speaker connector. The center pin is looking for a small conductor (20AWG or smaller) whether it's a solder type or crimp type. And the outer conductor really wants to see a braided shield (whether compression type or crimp type. That pretty much calls for a shielded cable. Plenty of uses in video, rf, or test equipment applications, but I've never seen BNCs in a guitar amp. Most guitar amp techs wouldn't have the patience or tools to put a BNC on a cable.

[eleventeen]

Yup. Wiring up TV production systems back in 75 ohm composite days I've crimped more BNC connectors than any human being needs for a lifetime.


A friend of mine and I got the deal to dismantle the old Metromedia (later, Fox, in its early years) plant on Wilton & Sunset Blvd. in Hollywood. Probably 35 miles of BNC cable, mostly fossilized RG-8 that had been sitting in cable trays for 25+ years, about as flexible as a steel rod. There were so many DA trays we just cut the cables in back of the connectors. What a task that was.

[shooter]

 [quote What a task that was][/quote]
You should try it in computer floors used in CAT and X-ray rooms after patients puke, lots of contrast dye that turns to concrete, add heat and well.......

[MFowler]

I will install a locking 1/4 speaker jack on high power amps on occasion.  Either plastic or metal is available.


http://www.parts-express.com/neutrik-nj3fp6f-p-1-4-locking-chassis-jack-plastic-housing--092-086?utm_source=google&utm_medium=cpc&utm_campaign=pla

[PRR]

> I would think the common two prong plug for a wall outlet would be best.

Yeah, until you have a tangle on stage, pull an end out and plug it in the wall, and your speaker gets 1,800 Watts.

We also used US wall-plugs for photographic flash. Find an extension cord anywhere. Get your cords mixed up, explosion or shock.

Speaker current through or wiring-to a British National (Navy??) Connector is absurd. These are terrible connectors for anything except their designed use (and maybe not even then). True, you can't pull the connector off, but with anything short of 1950s coax and braid-clamps you can pull the wire out of the plug. They come in two pin sizes which do NOT interchange.

XLRs will carry speaker loads toward 100 Watts but are not friendly toward non-round cable and would be confused for microphone connectors with bad results.

The PL plugs are robust but a real pain.

The SpeakOn is designed for the purpose. Ample for any guitar amp. Can't be confused with any other power or signal connector. Bulky, expensive, and very non-traditional.

The 1/4" is 'wrong' but everybody knows what it is. If you get good jacks (with firm contacts) it is maybe a better speaker-level connector than a line connector (where tarnish isn't blown-away by high current).

The old Cinch and Jones plugs could have been excellent. Fairly low cost (but too many production options which limited what you could really find in stock). Ample current, way more voltage than speakers need, good reliability, compact. One fault is that when part-in, you can drop a wire scrap across the pins.

[kagliostro]

Vox, in the old era, used this connectors, that seems to be a better choiche than the actual 1/4 jack



by Amphenol



I think they abandoned it because other brand adopted the 1/4 as a standard

something like when Betamax and Video200 where outclassed by VHS which technically was lower



Franco


p.s.: is to be say by Amphenol or from Amphenol ? Which is correct ? Thanks

[Willabe]

I would say, 'made by Amphenol.'


            Brad   

[kagliostro]

Ciao Brad

Thanks

Franco

[PRR]

> this connectors,..... by Amphenol

"XLR". There were several makers, with several part-numbers, all the same fit. I think Canon called them XLR, and eventually sold more of them than Amphenol.

Plug your microphone cable in. Fits perfect. Plug the other end into a sensitive microphone input. Now beat the guitar amplifier, burn-up your microphone amplifier.

Also they were $5 when a 1/4" was $1.

[Jim Coash]

I routinely replace RCA plugs whenever I re-build or acquire and amp for any purpose.  For line level I use XLR/Canon balanced when I can or 1/4" when I can't.  I like Speakons well enough and they are very good but I still install good 5-way banana binding posts on just about everything.  They are high current, you can feel the ground marker even in the dark, polarity reversal is easy and you can stack them when you want another cabinet in parallel. As a matter of course I keep all speaker wiring as short as possible and never use anything smaller than 16 gauge.  Most of my cables are 12 or 14.  When I run two speakers with long runs of wire I use the same length even though one is much closer than the other.  I never use a guitar signal cord as a speaker wire.  Most of my custom cabs have at least two options for connecting wire, some three.  !/4" is still the most common, the banana jack, then Speakons.  To avoid problems with shorting the 1/4" connectors I never plug in or out with the amp on.  I also pay close attention to impedance and load variances.  When using more the one speaker cabinet with an amp they are both either identical or I use one or the other not both together if they vary in efficiency more than 3 DB.  Shorts due to poor connectors or sloppy work have damaged many, many amplifiers.  When I make a service call, I never turn the system on to test it until I have completely re-wired it.  Much of the time, the problem described by the customer has already disappeared.