Reamp Box with Neutrik 10/3 transformer

[Whoops]

Hello,
I was in need for some Reamp boxes so after some research I found an article from an old magazine with a reamp circuit using the small and inexpensive Neutrik transformer model 10/3.

The circuit is simple to do (I did it point to point) and the Impedance pot and Tone pots are really useful.
It's a cool and useful box.

here is the schematic in case anyone wants to try the circuit:

 

[Whoops]

I need some more units of reamp so next I will try the NYD Reamp circuit and maybe the Scott Dorsey also

 

[scott2000]

https://groupdiy.com/index.php?topic=26943.0

 

[Dave B]

Thanks heaps for this. I saw & commented on your previous post but was wondering whether I have got this right from your schematic?
Couple of questions is the 470 impedance pot - OHM?
The 200 resistor i also assume OHM?
I think the rest of the layout i have correct although unsure about the ground lift wiring to the switch?

 

[totoxraymond]

Hi Dave,

Usualy, in a schematic, if no multiplier is written, then the resistance value is in Ohms. Sometimes the designer will use the letter 'R' for the same purpose. So for a resistor or a pot, '200' or '200R' mean 200 Ohms.

Regarding the ground lift issue, it seems to me that your diagram shows 'chassis' and pin1 from the input both connected together at the same pin of the switch. The purpose of the switch is to disconnect the shield from the sound card and the amp chassis to avoid ground loops if needed.

So you have to have either input pin1 or chassis wired to the common pin of the switch and the other wired to any of the other pins. (If using a SPDT switch, as shown in you diagram).

Hope this helps,

Thomas

 

[Dave B]

Hi Dave,

Usualy, in a schematic, if no multiplier is written, then the resistance value is in Ohms. Sometimes the designer will use the letter 'R' for the same purpose. So for a resistor or a pot, '200' or '200R' mean 200 Ohms.

Regarding the ground lift issue, it seems to me that your diagram shows 'chassis' and pin1 from the input both connected together at the same pin of the switch. The purpose of the switch is to disconnect the shield from the sound card and the amp chassis to avoid ground loops if needed.

So you have to have either input pin1 or chassis wired to the common pin of the switch and the other wired to any of the other pins. (If using a SPDT switch, as shown in you diagram).

Hope this helps,

Thomas

Thank you that does make sense. I always struggle when it comes to understanding switches (and as a result how to wire them!)

 

[Dave B]

Thank you that does make sense. I always struggle when it comes to understanding switches (and as a result how to wire them!)

Hey Guys - i have finally ordered the transformer and now getting the rest of the parts to build.

The 470k Vol Pot - having some issues finding them in australia - would 500k be fine? I am assuming so?

Likewise the 470 impedence pot - i am a bit confused here. Is this meant to be a linear 470k? or is it 470 ohm pot as per schematic? sorry for the many questions !

 

[kags]

Hey Guys - i have finally ordered the transformer and now getting the rest of the parts to build.

The 470k Vol Pot - having some issues finding them in australia - would 500k be fine? I am assuming so?

Likewise the 470 impedence pot - i am a bit confused here. Is this meant to be a linear 470k? or is it 470 ohm pot as per schematic? sorry for the many questions !

If you asking about the first schematic from Whoops, the pots are labeled LIN or LOG. 470 should be taken as 470 Ohms, as previous mentioned.

 

[Dave B]

If you asking about the first schematic from Whoops, the pots are labeled LIN or LOG. 470 should be taken as 470 Ohms, as previous mentioned.

No worries - comfortable with the Linear/ Log. Maybe my question wasn’t clear .

I can’t find any 470R pots in Australia and not seeing much anywhere else either so was just confirming.

Cheers

 

[Whoops]

Kags is completely right.

you can use 500K instead of 470K and also 500r instead of 470r, pots normally have between 10% to 20% tolerance anyway.

You can get the 470r/500r pots in Australia from element14 or mouser
https://au.element14.com
https://au.mouser.com

Mouser has a lot in stock:
https://au.mouser.com/c/passive-components/potentiometers-trimmers-rheostats/potentiometers/?mounting style=Panel Mount&number of gangs=1 Gang&resistance=470 Ohms~~500 Ohms&taper=Linear&instock=y&sort=pricing&rp=passive-components/potentiometers-trimmers-rheostats/potentiometers|~Resistance

 

[Dave B]

Kags is completely right.

you can use 500K instead of 470K and also 500r instead of 470r, pots normally have between 10% to 20% tolerance anyway.

You can get the 470r/500r pots in Australia from element14 or mouser
https://au.element14.com
https://au.mouser.com

Mouser as a lot in stock:
https://au.mouser.com/c/passive-components/potentiometers-trimmers-rheostats/potentiometers/?mounting style=Panel Mount&number of gangs=1 Gang&resistance=470 Ohms~~500 Ohms&taper=Linear&instock=y&sort=pricing&rp=passive-components/potentiometers-trimmers-rheostats/potentiometers|~Resistance

Thank you appreciate that . Mouser is a bit of a nightmare here for small orders (postage is insanely expensive) but that’s my issue ! Might have to wait till my next bulk order. Thanks again & look forward to putting this together

 

[Brian Roth]

Thank you appreciate that . Mouser is a bit of a nightmare here for small orders (postage is insanely expensive) but that’s my issue ! Might have to wait till my next bulk order. Thanks again & look forward to putting this together

Perhaps someone Down Under can suggest other vendors there...and add them to the "reliable vendors..." thread in the Lab section.

Bri

 

[cavedata]

Are you aware of Rockby electronics in Melbourne? They have em...
https://www.rockby.com.au/index2012.cfm

 

[Brian Roth]

Are you aware of Rockby electronics in Melbourne? They have em...
https://www.rockby.com.au/index2012.cfm

If they are a reliable vendor, perhaps add them to here:

https://groupdiy.com/threads/suggestions-for-reliable-component-vendors.88987/

Bri