RG-16 Problem

KDV

New Member
Hello!

An RG-16 in great condition came into my possession recently and I’m trying to set it up with the rest of my rig and results have been underwhelming at best..

The issue is that there is a severe difference in audio quality when going through the RG-16. (Way less gain, sounds like I have the tone knob all the way down, possibly a bit quieter than going straight in the preamp. )

Signal flows like this:

Guitar> RG16 front in>Back out>Buffer in>buffer out>Back In> Output>Engl e570 back input>Engl e570 Send>loop 5 In> loop 5 out> Engl e570 Return.

Nothing else connected on the RG16 Loops.

Have tried not using the buffer, same result with a bit more hum.

All cables are good, multimeter tested as per the posted guide here, <1 Ohm tip to tip and sleeve to sleeve, Infinite Tip to Sleeve.

Power is 12V DC, 1A Powersupply.

Am I doing something wrong here?

Grateful for any help, this is doing my head in.

Cheers,
K.
 
There's something wrong in the RG-16, it should pass audio transparently. First thing to try is to plug the guitar directly into Buffer In and see if that improves anything.
 
Thanks for the quick reply, much appreciated!

Actually yes, massive difference straight to the Buffer In, I think it sounds as it should there. I'll slowly start introducing pedals etc to the chain and check if all else is ok.

So what's the verdict? Fried input jack? Is there something I can check inside maybe or the jack needs complete replacing?


Also on a different topic on the same device, Rocktron all access straight into it's midi in does not work. All access to Tc Electronic Major- midi through to RG16 works fine. Is that normal?

Once again, many thanks for your help!
 
The front panel jack is connected by a short cable to the rest of the circuit. A common problem is the jack gets twisted and one or more of the wires breaks. That's probably the issue.

If MIDI is passing through the RG-16, the MIDI hardware is generally working. You probably have a channel mismatch where the All Access is transmitting on one channel, but the RG-16 is receiving on another.
 
The front panel jack is connected by a short cable to the rest of the circuit. A common problem is the jack gets twisted and one or more of the wires breaks. That's probably the issue.

Is that an easy fix or is the front input gone for good?

Thanks,
K.
 
Have you guys taken this to a private conversation?
KDV and I have been talking about this over at TGP

My RG-16 is squealing with high gain preamp settings in the serial loops
I have Mesa Boogie TriAxis and when the TriAxis is not running thru the RG-16, the squealing is gone
as soon as I get the TriAxis gain and drive above 5.0 the squealing starts
plus there is a possibly 25%+ volume drop thru the RG-16

My RG-16 is 2011 model; all mono

KDV was speaking of relay replacements being required.

Do y'all want me to start my own thread?
 
I don't know about the volume drop, which could be a few things, but the squealing is just going to happen with very high gain preamps whose outputs are in phase with their inputs. You could try using two loops to switch the preamp - for example, send 1 to the preamp input and the preamp output to return 2. This puts much more physical space between the send and the return, which will greatly reduce feedback.

Regarding the volume drop, try testing parts of the circuit at a time - if you're plugging into the front, plug into Buffer In instead. Use only a subset of loops for a while. Doing things like that will probably help pinpoint where the problem lies.
 
Ron, thanks for the quick response.

OK, I'll not start another thread :)

Well, I have three different preamps for selection with the serial loops
I have a Rock Master which also squeals like mad too....just like the TriAxis
Loop 1 sounds alright with a DigiTech GSP2101
I never use the TriAxis and Rock Master engaged in series at the same time
I typically have only 3 loops engaged at any one time (2 or 4 with FX thru 5 and 6)

I don't care for the buffer....but will give it a go

further, I suppose my first port of call is testing/ trying different cables...The cables in my routing are cheap TourTech brand cut down by me where I soldered new jacks where I cut to length and left the other end factory. I have some Mogami 2524 and can make some new cables.
When I "bypass" the RG-16, I'm using longer Klotz La Grange and SpectraFlex cables....that could be an issue...

All I'm really bypassing on the RG-16 is Input (front panel)>From front>Input (rear)>Loop2 send>

hmmm, now that I look closely, I have a cheap Hosa-type knock-off moulded cable patched From Front to Input Rear; that might be a good starting point!

I'll report back after some more trouble shooting
 
Last edited:
I dug into my squealing issue a bit today:
1-I don't notice any difference with or without the moulded, hosa type knock-offs

2-connecting Guitar Out to RG-16 rear Input I notice no difference compared with the front panel Input and a cable From Front>rear Input

3-Using only RG-16 serial loop sends direct to preAmp the squeal is gone; it is a little bit more noisy than w/o RG-16 (maybe a ground loop I haven't tracked down yet)

4-as soon as I connect a serial loop Return I get massive squeal. I only tried Loops 2 and 3, so far

I didn't try 2 loops or any parallel loops yet. I probably have to disconnect everything and restart my routing

also, I have confirmed I am powering the RG-16 with 9V AC via a Yankee HS-M12.
 
I think it's just the fact that it's a very high level, high gain signal and it's feeding back through the relay or the jacks used for switching. Using two loops is probably the most likely way to fix it.
 
TriAxis settings are 5.5-6.0 on Lead 2 yellow or red and overall gain over 5.5? And that's too high?
Similar settings on the Rock Master...probably just a little hotter

I'll try 2 loops and report back...
 
TriAxis settings are 5.5-6.0 on Lead 2 yellow or red and overall gain over 5.5? And that's too high?
Similar settings on the Rock Master...probably just a little hotter

I'll try 2 loops and report back...
The design of the preamp is much more relevant to this problem than the actual control settings. A Triaxis is a high gain preamp for sure!
 
OK, so I ran thru a couple more scenarios

I tried using RG-16 Send 2 out to TriAxis Input> TriAxis output to RG-16 Loop 4 return and squealing is the same as using the same loop. I also tried Send 3 to Rtn4 and also Send2 to Rtn3; squealing remains

I tried changing power from 9V AC to 12V DC (using Yankee HS-M12) and still no change to the sqealing

then I tried different guitars. I found my one guitar with a potted PU (Heartfield RR-8) does not squeal with the RG-16..
All my other guitars squeal:
-MIJ Strat with SD Quarter Pounder (offset)
-Gibson Byrdland with stock PAFs
-Epi LP 7String with stock PUs
(I didn't try the others)

they all squeal like mad when using RG-16 returns 2-4
and these same TriAxis settings w/o RG-16 or using the RG-16 input and sends only do not squeal
as soon as a RG-16 Return is in the routing, it squeals

so it seems like it is the RG16...as my RG-16 is not transparent; it SQUEALS!!!

My Masotti MXM does not create this squealing, BUT I don't use the returns....I could try that next, I suppose
 
Interesting. If the guitar is involved, then that changes everything. The guitar itself is in the feedback path, so whatever is going on is not entirely internal to the RG-16.

Does it squeal when you turn down your guitar volume all the way?

If you have an ohmmeter, it would be helpful to measure resistance between the RG-16 enclosure and ground. Unless you're the first owner of the RG-16, we don't know its history and it's possible that someone lifted the ground internally, making the enclosure unshielded. You may have to dig the probe into the RG-16's face plate a bit to get a good connection - the metal is anodized, which is an insulator. The ground you can get from a screw on your power conditioner, an amp chassis or the like.
 
Hi Ron,
thanks for the quick response

to clarify: I only get squeal with a guitar connected
if the volume is all the way to zero the squeal stops- for all the guitars tested which squeal

with the single coil Seymour Duncan Quarter Pounder the squeal pitch changes (pitch frequency rises as the pot is turned down)

I bought this RG-16 used in Feb 2019 from a guy in California. I am in France.

I've been trying to get a resistance measurement as you suggest. I need to unrack the power amp I use for dry as I'm not able to access the chassis of that amp (VHT 20562) with it in the rack. It's in a rack all by itself, so isn't a huge undertaking.

My rig is complicated with two VHT power amps feeding 4 cabs in a WDDW scenario. I have a VHT 2562 and a 2902. Everything is powered via an APC BackUPS Pro 1500 except the 2902 which will exceed the wattage of the APC. That's why I should test resistance to the 2562 because it's powered by the same unit as the rack.

I can get a measurement of resistance between a screw on the top of the 2902 and the RG-16 if I touch the probe on the RG-16 to the RG-16 metal behind the faceplate which is around 002.8 ohms. Other screws on the 2902 or on the face of the 2562 give variable numbers that are all over the shop. My Extech EX350 is set to Auto...so I don't know if the DMM is struggling to sense the format to read? I don't know.

I probably need to measure the volume difference with a decibel meter to get some real data.
 
I suppose my question is really whether it will be worth it to replace the relays in the RG-16 or just call it a day on the RG-16 and get it out of my rack. I'll need another loop switcher or alternative. I do know of a method with the FX Loop on my DigiTech GSP2101 which may deal with my current switching needs. I suppose I could try to acquire a MEGX...but they are 670euros and I imagine new relays for the RG-16 would be a lot less
 
I still can't figure out what's going on here. The fact that the problem doesn't happen with one guitar is what's most puzzling.

Whatever it is, it's quite unlikely that replacing the relays will fix it.

Have you tried bypassing the front input and plugging straight into the buffer input on the rear? The connection between the front panel jack and the circuit board is a common point of failure. I would expect that breaking the ground wire would cause a complete loss of signal, but maybe it could cause other symptoms.
 
Hi Todd/Ron,

Is this a ground loop issue? That can cause squealing when there is a lot of gain involved. Think of your ground plain in the system like a party balloon. As the currents and things get higher, it will burst.

The way you it seems have it, you're sending the tip/sleeve connections back and forth to the RG-16 several times, interconnecting several grounds and a very hot signals between the preamps and the switcher.

Be interesting to see a diagram of this. It seems an unusual way to connect the preamps, and imo is not ideal. If it were me, I'd have a buffer/splitter like an Axess BS-2 splitting the guitar signal between the RM and Tri front ends.

Then you could use one loop (5-8) of the RG-16 to A/B the outputs of each preamp to whatever your next source point is (sounds like send switching only to post preamp effects?). You only need one loop to A/B two preamps. It has to be a full loop, like 5-8.

Assuming the config of the loops 5-8 are the same as a GCX, Axess GRX4 Loop #4 etc, one preamp's output will go into the loop's input, the other preamp's output into the loop's return, and the loop's output goes to the next source (unlike a GCX, I think the RJM configs to the input of the next loop along - the GCX, you have wire it). The loop's send is left unconnected. Switching the loop on/off A/B's the outputs of the preamps.

The RG-16 has relays, doesn't it? Relays are transparent. It doesn't matter who makes the switcher. There's something else going on in there.

Just my 2 cents.

Chris.
 
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