RV50 FX loop

jamison162 · Post by **jamison162** » Wed Dec 10, 2008 7:25 pm

Nope, no tonal difference when the loop is active or bypassed.

kornel · Post by **kornel** » Wed Dec 10, 2008 8:00 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by TeuF
 Hi all,

To avoid everyone confusing and chatting about which pedal is sucking so much life from the RV50 while in the FX Loop, just try to put a jack (a PlanetWave in my case) from "Send" directly to "Return" and you will notice the same sucking tone thing (in my case again).

Don't you ?

Any Orange tech to answer the question please ? Perhaps some mod can do the thing (cap, etc)..

<hr height="1" noshade id="quote"></blockquote id="quote">

Salut TeuF!
I did the same experiment that you've described here. I encourage you to repeat it with DIFFERENT CABLES. I tried some of them - some resulted in tone sucking, some others even hummed! I know PW is an ok brand, but plug in all the instrument cables you have - let us know if the results were the same.

-Kornel.

miles · Post by **miles** » Wed Dec 10, 2008 8:11 pm

i get it no matter what cable i use. cuts tone and signal. I tried everything from GL, Planet waves, dimarzio... i build all my own cables for my rif with nuetrik parts.. same deal. its not a pedal or rack unit doing it to my orange.

jkstigma · Post by **jkstigma** » Sun Dec 21, 2008 10:36 am

hey man...
maybe you have to try..Evidence cables

tayholliday · Post by **tayholliday** » Sun Dec 28, 2008 7:23 am

Since someone hasn't answered this original question correctly, I will

. I've done extensive research into this because of the frustration with my RV50's fx loop for the same reason. The problem is that the RV50 (and probably the RV100's) effects loops sends are high output impedance, as confirmed by correspondence with Will Loftin of Orange USA. Most other modern effects sends are low-z. Mesas don't have this problem. Neither do marshalls. Neither do peaveys. All their effects sends are low-z.

High-z outputs, like a passive guitar pickup, don't travel well over long cables and are sensitive to the type of cables used. Audio equipment designers have been avoiding high-z for a very long time.

To see how dumb the RV50s effects loop is... just complete the loop with a 20' guitar cable. You will notice a significant reduction in high frequencies. This is most noticeable when playing with distortion. Its like throwing a sheet over your amp. Now try the same thing with a Mesa (my brother has a Stiletto)... no noticable change.

Furthermore, most rack effects will actually sound really bad in the RVs effects loop because of their low-z inputs. After all, they expect normal low-z effects loops. Some however may have high-z inputs (such as the TC G-force). Many pedals have high high-z inputs and so you're ok... BUT only if you've got a short cable run between amp and pedal!

My solution was to use the Radial Big Shot pedal as the first thing in the loop. Its got a variable impedance input that allows you to dial out the lameness of the RV50s effects send. And its also bright orange!

This idiotic design wasted a lot of my time! Remember, the problem isn't the cables!

I would love an Orange engineer to explain why they chose this design.

afrodisiac · Post by **afrodisiac** » Sun Dec 28, 2008 4:21 pm

thank you

i posted this question AGES ago, and have already reached the same conclusio as the above poster since that time...and now i also run a buffer pedal after the send, in fact i have that buffer permenantly there before all my amps, it doesnt hurt having it there...the tone sucking improves massively but its still there but doesnt bother me so much anymore

thanks for your comment anyway

Guitarted · Post by **Guitarted** » Sun Dec 28, 2008 9:37 pm

I recently purchased an RV50 head, and I've noticed the same thing with the FX loop. When I use the loop, I lose a lot of high-frequency in my guitar tone. I even lose tone when simply running a 10 foot cable from the send to the return. I know that cables and effects will change/degrade the tone somewhat, no matter which amp is used, but I'm amazed at how much of a difference it makes with the RV50. I've never experienced such extensive tone loss with Marshals, Mesas or Peaveys. I'm disappointed by this, and I'm surprised Orange hasn't addressed this problem yet.

For my purposes, this FX loop is entirely useless.

This is a great sounding amp though, and I can still run effects through the front, so its not all bad. However it would be nice to have a good FX loop to get the best sound out of modulation effects.

a.hun · Post by **a.hun** » Mon Dec 29, 2008 4:55 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by tayholliday
 ...I've done extensive research into this because of the frustration with my RV50's fx loop for the same reason. The problem is that the RV50 (and probably the RV100's) effects loops sends are high output impedance, as confirmed by correspondence with Will Loftin of Orange USA....

I would love an Orange engineer to explain why they chose this design.
<hr height="1" noshade id="quote"></blockquote id="quote">Well that would certainly explain it. Have been wondering myself why the RV's wonderful valve driven loop was such a persistent source of complaints... [:0]

Why did they do it? You want to phone up Orange UK and speak to Ade Emsley on that one. He did it!

Ade is a very good and very well respected amp designer, but that one was maybe a slightly curious choice. My guess would be that he is a pedal kind of guy rather than a rackman, and that he probably knows how to use a buffer right and thinks everyone else does too.

This is definitely one situation though where your (supposedly) 'true bypass' pedals won't shine on their own. As you say even a good lead will degrade the Hi Z (= high impedance) signal ..

NDH. (Hi Z, low Z, no Z, Rocker.)

a.hun · Post by **a.hun** » Mon Dec 29, 2008 4:57 pm

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by flea
 It also only takes one pedal to ruin the whole batch...
<hr height="1" noshade id="quote"></blockquote id="quote">Seems that "It only takes one pedal to FIX the whole batch" would probably be closer to the truth!

A carefully placed one with a good buffer that is... [:0]

NDH. (Rocker.)

Norrin Radd · Post by **Norrin Radd** » Tue Dec 30, 2008 3:52 am

Huh. I have had my RV50 for 3 years. I've run all manner of modulation and time based effects in the loop. I have tested the tone meticulously each time I put something in the loop - on both channels. I just cannot get my loop to suck any tone. It's not just me either. The other guitar player in my band - he builds amps as a hobby. He LOVES the loop on my RV50 and is cloning it for his own build.

Seriously, I've tried pedals, rack effects and even PODs in the loop, all without any noticeable tone loss (outside of the PODs inherent tone failures, but I digress). Did I just get lucky? Did I get an anomaly? Has something changed in the design over that time? I'm really curious - I have to find someone else with an RV50 and check it out........

a.hun · Post by **a.hun** » Wed Dec 31, 2008 11:57 am

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Norrin Radd
 Huh. I have had my RV50 for 3 years. I've run all manner of modulation and time based effects in the loop. I have tested the tone meticulously each time I put something in the loop - on both channels. I just cannot get my loop to suck any tone. It's not just me either. The other guitar player in my band - he builds amps as a hobby. He LOVES the loop on my RV50 and is cloning it for his own build.

Seriously, I've tried pedals, rack effects and even PODs in the loop, all without any noticeable tone loss (outside of the PODs inherent tone failures, but I digress). Did I just get lucky? Did I get an anomaly? Has something changed in the design over that time? I'm really curious - I have to find someone else with an RV50 and check it out........
<hr height="1" noshade id="quote"></blockquote id="quote">Yeah I'm curious too. Is it just down to having a good buffer in the loop, or has something actually been changed in the loop circuit.

Fortunately for me I'm not FX loop dependant, but it is a really good question. Wonder what Ade would have to say on it...

NDH.

a.hun · Post by **a.hun** » Tue Jan 06, 2009 10:27 am

Found this which might be of help:
<blockquote id="quote">quote:<hr height="1" noshade id="quote">From:
http://www.aikenamps.com/
--> Tech info
--> Technical Q+A
--> (Just below 1/2 way down that page)

Q: My amplifier effects loop output impedance is 100 ohms, but my effect has an input impedance of 1Megohm. The effect output impedance is 1K ohm, but the amplifier return impedance is 220K ohms. How do I get them to match, and is this important?

A:Beware - you don't match impedances when dealing with low-level signals like you do when using a power amp and a speaker!

In a low-level signal application, you want maximum voltage transfer, not maximum power transfer, so the "ideal" situation is a zero output impedance from the driving source going into an infinite impedance for the receiving end.

Your amplifier send impedance of 100 ohms is very low, so it is near "ideal", and the 1Meg input impedance of the effect device is very high, so they are a good match because you will not lose any appreciable amount of voltage - if your amplifier effects send puts out a 1V signal, you'll get 0.999 volts at the input to the effect unit.

The output impedance of the effect device is 1K, which is still fairly low, so driving into the return of the amplifier, which presents a 220K load, you'll only lose a small amount of voltage - if the effect puts out a 1V signal, you'll still get 0.995 volts at the amplifer FX return, so they are well-matched.

If you have an FX loop with a high output impedance or an effect with a low input impedance, you'll need to use a buffer between the loop output and the effect input. Likewise, if you have an effect with a high output impedance or an amp with an FX return with a low input impedance, you'll need to use a buffer between the effect output and the amp loop return.

In general, if the source impedance is at least 10 times lower than the load impedance, you're okay, because you'll get 90% of signal transfer. The lower the source impedance, the less high end you'll lose due to cable capacitance or load capacitance on the input of the effect, so the closer you get to a zero ohm source impedance, the better.

The problem that usually occurs with instrument-level effects like pedals in loops is that you have to attenuate a large signal swing down to the level of a guitar pickup signal so you don't overload the pedal effect (which is designed to go inline with the guitar and amp input) and then amplify it back up to a large level to drive the return side. This will greatly amplify any hiss at the output of the effect and any noise present in the chain, which is why it is best to use line-level effects in an amplifier fx loop whenever possible.

Ironically, most tube manufacturers use tube buffers for the send and receive of an fx loop (to keep the all-tube "purists" happy), but you can get a much better noise floor with modern low-noise opamps in the loop circuitry. Since the effects are 99.9999% solid-state anyway, it really shouldn't matter, tone-wise, if the loop is solid-state (as long as it is relay-bypassed when not in use).<hr height="1" noshade id="quote"></blockquote id="quote">

NDH.

RV50 FX loop

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