Home » Audio » Pro Sound » Channel jumping inputs fender to Matchless
Channel jumping inputs fender to Matchless [message #27024] Sat, 30 April 2005 00:54 Go to next message
walters is currently offline  walters
Messages: 14
Registered: May 2009
Chancellor

1.) What happens when i daisy chain inputs?
or channel jump the channels from different
amp designs?
a.) Does the impedance get mismatched?
because the two amps have different
circuits and are different designs?
b.) Does it change the Frequency Response?
c.) Does it load down the inputs?

example: guitar goes in fender normal input#1
jack.normal input#2 jack goes to a
Orange amp input jack#1 with a daisy
chain cord.
input jack#2 of orange amp another
daisy chain cord goes to a Matchless amp
input jack#1

2.) The Signal parallels off to the other amp but
is there any REFLECTED load current or voltage
when channel jumping?


3.) Does anyone know any cool Channel jumping
path ways?



Re: Channel jumping inputs fender to Matchless [message #27028 is a reply to message #27024] Tue, 03 May 2005 11:32 Go to previous messageGo to next message
Damir is currently offline  Damir
Messages: 1005
Registered: May 2009
Illuminati (2nd Degree)
Two-channel inputs ("normal" and "low") are in 90% cases made of two 68k "input" resistors in series with input grid and one 1-Meg grid leak resistor, see the typical "Fender" schematics. Input 1 ("high", or "normal") has input impedance ~1Meg (ignoring 68k resistors for simplification), and input two ~2*68=138k. When you connect 3 amps in a way you described, you`ll get the total input impedance ~1Meg/3 ~333kOhms. With high-impedance source (guitar PUs) you can count on some high-frequency loss/change of sound (with little help with all those cables, too). But, you can often count on a ground-loop buzz, and hiss,too.
Then (non-identical) signal phases through 3 amp together can give you weird effects sometimes. But, often the sound is full and good:-)
I tried even some swither/multioutput/impedance converter devices, mixer/line outs, FX loops...but I was never quite satisfied with the results (sound/noise, even oscillations/radio stations, haha) with unequal old amps...but, try it and see.:-)

Re: Channel jumping inputs fender to Matchless [message #27029 is a reply to message #27028] Tue, 03 May 2005 11:47 Go to previous messageGo to next message
walters is currently offline  walters
Messages: 14
Registered: May 2009
Chancellor

Don't your get a different voicing from each amps input impedance?

Re: Channel jumping inputs fender to Matchless [message #27031 is a reply to message #27029] Tue, 03 May 2005 12:07 Go to previous messageGo to next message
Damir is currently offline  Damir
Messages: 1005
Registered: May 2009
Illuminati (2nd Degree)
It`s a "primitive" 3-way "Y" cable, the resultant sound can be "big and full", but ground-loops problem I never resolved. I had even the "guitar rack" full of everything and once blowed brand new "Drawmer" compressor...there are some sophisticated ways (signal "splitter"/booster/mixer), but I forgot almost all about it:-)
In rarely occcasions when I play the guitar, I use just the "blackface" Deluxe Reverb (in the last 10 years). And yes, I used with good results M.Boogie "Studio" preamp for that "stereo" things - 2 output for two power amps and two guitar boxes.
Try and see, the same power outlet for all amps and check for possible AC difference between the "masses" of the amps...

Re: Channel jumping inputs fender to Matchless [message #27033 is a reply to message #27031] Tue, 03 May 2005 12:21 Go to previous messageGo to next message
walters is currently offline  walters
Messages: 14
Registered: May 2009
Chancellor

If i Y Cord 2 amp channels whats the difference in impedance
from a Y cord to 2 amp channels and Daisy chaining 2 amp channels
the impedances are both different

1.) Y cord impedance going into 2 amps channels?

2.) Daisy Chain inputs going into 2 amp channels impedance?

3.) Im looking at it in a impedance way Y cord VS Daisy Chaining
input channels



Re: Channel jumping inputs fender to Matchless [message #27034 is a reply to message #27033] Tue, 03 May 2005 12:36 Go to previous messageGo to next message
Damir is currently offline  Damir
Messages: 1005
Registered: May 2009
Illuminati (2nd Degree)
Google search with "key" words guitar, splitter, buffer, etc. can give you tons of answers, for example you can check "Harmony-Central" and reviews of such devices, for example "Axess Electronics" BS2 Guitar Audio buffer/splitter...
And I found some FAQ:

Re: Channel jumping inputs fender to Matchless [message #27036 is a reply to message #27034] Tue, 03 May 2005 12:45 Go to previous messageGo to next message
walters is currently offline  walters
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Registered: May 2009
Chancellor

No i want to know about the impedance of it the Y cord VS daisy
chain what is the Impedance Difference and how does it work the
difference between Y cord VS daisy chaining 3 or 5 amps input channels together?



Re: Channel jumping inputs fender to Matchless [message #27037 is a reply to message #27036] Tue, 03 May 2005 13:18 Go to previous messageGo to next message
Damir is currently offline  Damir
Messages: 1005
Registered: May 2009
Illuminati (2nd Degree)
In both cases, all your input impedances are paralelled, if you have two amp with "Y" cord, or "daisy chaining" them, input guitar cord would "see" about 1Meg/2 = 500kOhms in both cases.
Must go now...

Re: Channel jumping inputs fender to Matchless [message #27038 is a reply to message #27037] Tue, 03 May 2005 13:30 Go to previous messageGo to next message
walters is currently offline  walters
Messages: 14
Registered: May 2009
Chancellor

I thought Y cord was different because its not using the other
68K resistor in the Low input mostly used on amps to daisy chain

Daisy chain uses both jacks using both 68K resistors
example- guitar goes into 68k input resistor hi input jack
The Low input jack 68K input resistor is daisy chained
to the other amps channel input so there is another
68K

So Daisy chain uses 3 input 68K resistors so the impendances
is different because there is 3 68Ks resistors in parallel


The Y cord just uses 2 input 68K resistors i don't know if its in
parallel i know the signal from the guitar is parallel to the
amp channals
example: guitar output gets Y cord the Y cord splits to Two
different different amps channels one being a marshall
and other amp being a fender amp. So there is only
2 68K resistors and not in parallel i think


So the Y cord uses 2 68k resistors

The Daisy chain uses 3 68K resistors in parallel or more if you
have more and more amps

So the impedances are way diffeerent from using a Y cord than
Dasiy chain

what do you think im guessing here

Re: Channel jumping inputs fender to Matchless [message #27039 is a reply to message #27038] Wed, 04 May 2005 12:44 Go to previous messageGo to previous message
Damir is currently offline  Damir
Messages: 1005
Registered: May 2009
Illuminati (2nd Degree)
If we count in 68k resistors (and we should), then the situations are like that:

a) 2 amps, both input 1 with Rin=1Meg with "Y" cord - guitar "see" the two 1Meg loads in parallel, or 1Meg/2=500k. Three amps - 1Meg/3=333k.

b) 2 amps, "daisy chaining" - guitar in input 1 (Rin=1Meg), then out through input 2 to the second amp and its input 1 again (Rin=1Meg). BUT, we now have two 68k resistors in series between inputs 1&2 on the first amp, or in another words, guitar "see" 1Meg in parallel, then 2*68k=136k in series, then 1Meg in parallel. The resultant resistance is now (1000k+136k)//1000k = 531,8 kOhms. Not much of the difference, but if we connect the third amp on the same way (another 2*68k in series, and 1Meg in parallel) then resultant resistance is (531,8+136)//1000k = 400k, larger then "triple" Y-cord result of 333k. But, first amp get full signal voltage, and other two little attenuated signal through 136k/1Meg combinations.
Normally, this is correct if the inputs are wired at the same way, you can try it with ohmmeter, amps switched off, cables installed.

-All in all, you can try both solutions, but personally I don`t like either of them, as I said, our tiny voltage/high impedance source (guitar PUs) probably needs better solution, see splitter, etc, theory.

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