Thank you! Have a great time building!

​@@LifeHarmonic can I send you the scheme and you tell me if is correct?

​@@LifeHarmonic I was just about to subscribe but I noticed you haven't done a video in 4 years, is that correct? Did you change to another channel name maybe? Hope you are ok and doing well. Peace from Ireland mo chara.

Thank you for watching!

Thanks for watching! Yes, you can ground one of the connectors to the chassis, either XLR or Jack. The noise should go away. :)

Volume controls are generally set up as a volume divider, this impedance adjuster is just adding series resistance.

Thank you very much!

Thank you for watching! If the parts are the same, the signal should only distort at the levels and frequencies shown at the end of the video (20Hz-40Hz with high levels), it should not be thin. At what frequencies are you starting to see a drop in level?

would be great to know if you did this !

Thank you! Yes, you can use the same transformer, it will work just as well.

Im just using my knowledge from reading amp forums, its probably working like it does in a presense knob for an amp, when you move the switch you can hear a crackling like noise because its biasing the circuit and thats actually DC voltage you hearing on the pot. Its probably normal operation but yeah mabye someone else can chime in. Hope this helps.

You could use it as a DI box, but it has a fairly low input impedance and would need a buffer (or a buffered pedal) before it. It's not an optimal way to do DI though, you would need a different circuit with some active components to get the best results when you plug a guitar straight in.

@@LifeHarmonic alright, thanks for the answer!

It should work with this transformer as well, just the minimum output impedance will be slightly higher, but for most reamping purposes it won't make a difference.

Disconnecting ground can and usually will improve noise performance quite a lot, but if you're asking why would you want to connect it in the first place, the answer is: if you are connecting two pieces of gear, each grounded somewhere (this is normally at the wall socket), you don't need (or better, don't want) to connect ground between them as well. But if one has no ground (maybe you're using a laptop with a USB powered soundcard, or the device being re-amped is battery powered/has two prong plug with no ground), it doesn't hurt to have it connected.

This is my question too. Did you come to any conclusions?

Thanks! It's not absolutely necessary, but as you can see at the end of the video, a directly connected signal (ground) may result in a lot of noise.

Thank you for watching! The transformer is not the only way to change impedance, in fact in modern equipment transformers are rarely used (since their price is high and size is impractical), so most of the impedances are set by a fixed resistor. When you get a -10dB switch (or any attenuation switch) on a device it is usually just a resistor divider that is engaged. The end output impedance is just the value of a series resistor with the output amplifier or in case of an attenuation switch, you have to calculate it from the two resistors used. This is why in my build, I use a variable series resistance to adjust the output impedance and the reason that the potentiometer is wired like it is, is so that the load on the transformer is always constant (always 100k ohm). If it were to be wired just as a variable resistor in series with the positive rail, the variable load on the transformer would change it's frequency/distortion characteristics when turned.

@@LifeHarmonic fantastic vid! thank you

@@LifeHarmonic didn’t understand anything but sounds like you know what you are doing! Although I don’t understand why we have to add a ground switch since ground connected makes so much noise…

Hi, you can contact me via e-mail and I will send it to you. Thanks for watching. :)

Thanks! It's not really necessary to include the switch, you could hardwire it in the "lifted" position. With the switch, you can ground the whole system if, for example, you're doing reamping via a laptop that has no ground connection.

@@LifeHarmonic Thank you for the answer! I will build it including the switch then since it helps with different situations! Btw why do we need a volume knob since we can change the output volume from the computer? So far I've been recording noisy small guitar parts straight from the FF800 adjusting the volume by ear, how do u adjust properly? Thank you for the time again!

@@TheCoreys It's not a volume, but an impedance adjustment knob. For some pedals, like a fuzz face, it makes a big difference to the sound if the source impedance is low or high, and for those situations, it's great to have this control to fine-tune the sound. As far as the volume is concerned, it really depends on what you want, but most of the time it works by ear. If you record with no gain and then reamp at 0dB it should be pretty close to what the guitar originally put out.

Haha, "I think". That's hilarious, because the video caused you to spend money. Did you get it built? How'd it go?

@@gillihansmobilewelding Spending money on tools isn't THAT bad :=)

Thank you! Sure, you can do that, just watch the wiring, because 3.5mm is usually stereo and you have to connect it as mono. Tip + Sleeve wired together and shield as ground. Then it will work just as well.

@@LifeHarmonic I saw you are using enclosed socket in both in and out.. so I guess it's not necessary to ground the casing?

@@powerofsempol2905 Actually, you can ground it on one side of the transformer only. For most reamping purposes there will be almost no difference, but if you're sending the signal through an amp with a lot of gain it's better if it's grounded on one side. Should have mentioned it in the video...

Hi George! The pot emulates guitar output impedance, so if it is all the way to the left, the output impedance is very low (like you would have an active guitar), somewhere in the middle (if you have a logarithmic pot) is just about 10k which is a passive guitar on full volume, and all the way to the right is about 100k, which is like a passive guitar volume set to 5.

@@LifeHarmonic Thanks a lot!I'll try it!

Thanks for your question, that would really depend on what is the source of the signal. It could be just a resistor divider but I cannot make a helpful suggestion if I dont know the source device. :)

You connect it via a standard XLR cable (Line Out from your soundcard/audio interface) and then use a 1/4" jack cable to your guitar amp/pedals. You can adjust the impedance by turning the potentiometer (clockwise is higher impedance).

@@LifeHarmonic Thanks for your answer! I will order parts and try to build one.

Acrylic lacquer?

@@-______-______- yes

Technically it is possible, but it's best if fx loop is solid state so that output impedance is fairly small. And typically there are female XLR connectors on the outputs of devices, but you could make this work if you chose a jack instead of an XLR or a cable with a male XLR to TRS jack.

It's probably going to work just fine with a plastic box. If you have noise you can shield it later with copper/alu tape or conductive paint.

@@LifeHarmonic Yeah! Noob worries I guess hehe! I saw someone the other day build a complete tube amp and he started the build on a template, a piece of MDF I guess, with all the holes drilled etc. Then he did all the soldering and after THAT he moved the whole cake of components and wires into the box, like "the eagle has landed!". That looked plenty smooth!

Yes, a stereo jack will work just fine instead of XLR. In fact, since I'm using mine with RME Babyface Pro most of the time, I have a jack-XLR cable just for reamping and it works great.

@@LifeHarmonic Thanks!

The gauge doesn't matter, since the power transmitted over these wires is really small, you can use anything. I will add the link to the knob in the description. Have a great day!

@@LifeHarmonic thank you very much!

The knob doesn't act like a volume knob. It's adjusting the output impedance, from just a few ohms to about 100k ohms. This is simulating a guitar volume pot when turned, which is very useful if you're reamping a guitar and the pedal you plug the reamp box in is a fuzz face or something similar that is sensitive to output impedance. In that case, with increased output impedance, fuzz will clean up, which would be impossible with just adjusting the volume digitally on the computer. You can do all volume adjustment in your software or directly on the sound card.

@@LifeHarmonic oh ok, thank you do so much for help! Great video btw! Looking forward to future videos!

@@filipmakesthings thank you, have a great day!

@@LifeHarmonic thanks for the info! and what is the position of the knob where I am not affecting the impedance? the lowest, in the middle or the highest?

@@myyt4382 The left most position is the lowest output impedance. It's impedance is then much lower than that of a passive guitar when on full volume. When the knob is on 12 o clock, it's impedance is about 10k, which is about the same as a passive guitar with it's knob on 10, and when it's fully up, it's similar to a passive guitar with it's volume on about 7 (this really depends on what kind of pots the guitar is using, logarithmic or linear taper).

Yes, it works with any amp. The signal coming out should be almost exactly the signal coming in to the box, meaning, the level you're sending to the amp is dependant on your soundcard volume settings. If you record guitar without any gain added and then play it back through the reamp box at full volume, the signal should be about the same as the guitar when recording (that is if you're using a 1:1 ratio transformer like the one in the video. If you're using any other ratios you can have different levels).

@@LifeHarmonic thank you for your quick answer. Yes I used the same transformer. I think I need to check my welds and soundcard specifications.

One more question the output signal of your sound card is stereo ? You have a stereo jack to XLR cable ?

@@baarbak8188 It's a mono jack to XLR cable (it's configured as mono even though it's a stereo connector).

@@LifeHarmonic ok si it means that it works only if your sound card output is balanced. Not like me using 2 x RCA unbalanced monitor output.

Im using a TRS to xlr cable to go from my audio interface (Focusrite 6i6 - I believe its a balanced output), is this the problem... should it be a TS-xlr instead?

It should not matter which way the transformer is if both sides provide equal impedance. If everything is wired correctly (TRS to XLR is fine, just keep in mind you have to connect Tip and Ring to the the pins 2 and 3 of the XLR) it should work with a 6 pin transformer just as well. So I wouldn't know where the problem is, maybe you can take a picture of the wiring?

@@LifeHarmonic Thanks for getting back to me! I have sent you a photo of the wiring to your email, would be a massive help if you could take a look! :)

​@@georgebloomfield86 I built one and have same problem and same interface, how did you solve it?

It can work a little like a tone control with long cables or high capacitance inputs, although it should not be as noticable as a guitar's tone pot.

Yes, they are connected together. They don't necessarily need to be, both are connected together mechanically when the jack is unplugged, but then one side disconnects when the jack is plugged in. This function is not needed here, so I just connected them together.

@@LifeHarmonic Thank you very much. I have my pedal built at this point, just need to solder the connections. You tutorial is very good and I hope to be able to complete my pedal soon.

@@LifeHarmonic my 1/4” jack only works when the cable is plugged in half way. I am using a mono guitar cable. Is that the way it’s designed. Also, what is the pot knob supposed to do? Mine doesn’t seem to really have an effect to the signal when I turn it. Thanks!

@@MichaelMyersDoverPA Maybe you're using a stereo jack socket and it's wired to pick up signal from the RING on a stereo cable. The pot is supposed to alter output imepdance. In most situations this won't be noticable, where you would really see the difference is if you used a Fuzz Face or a similar fuzz pedal and some WahWah pedals directly from this reamp box.

@@LifeHarmonic Thank you for getting back to me, and I probably purchased a stereo jack by mistake when ordering the parts for the build.

Scarlett 2i2 has balanced outputs, so you connect TRS (this is a stereo connector, mono would only be TS)-> XLR like this: Jack tip to pin 2, jack ring to pin 3 and sleeve to pin 1.

@@LifeHarmonic Thanks a lot for the help my friend, I really appreciate it!

You can use a 1M pot, but if it's a linear pot, the only really usable range will be less then a quarter turn. You can also go without if you don't use fuzz or similar pedals for reamping.

You mean in the oscilloscope? I think he just offset the scope inputs 180º to see the difference easier.

I have the same situation, so I made a cable TS -> XLR. Just wire the tip to pins 2 and 3, the ground to pin 1 and it will work. You can also use a normal mono jack connector instead of an XLR in the box.

@@LifeHarmonic Will this cable compromise create unnecessary noise? isn't the line output of the interface unbalanced, and it will go to the input of reamp box which is balanced, right?

@@divinodayacap3313 No, it won't create any extra noise. You are using a normal unbalanced instrument cable to connect from the reamp box to the amp anyway. Just make sure to keep the cables as short as necessary.

@@LifeHarmonic Is it really necessary to have plastic Xlr and TS Jacks? I just bought metal ones already. haha sorry I'm a noob at this :(

At least one of them should be plastic, otherwise you will connect ground directly through the chassis. It is possible that XLR connector is metal and it's casing is not connected to any pins, if that's the case, it should work. You can check that with a countinuity test on a multimeter.

Ok i used an old pedal box to give me more space for the pot i have. Could you please tell me which way the switch is facing? cuz if i have it 180 degrees from the way you have it, then i will be soldering the wires on the wrong contact points. or am i confused? I'm very new to this. Cheers

Sure you can use a logarithmic pot as well. New videos on DIY gear are coming really soon and they will include distortion pedals as well!

The ground lift switch is not really important how you wire it up, meaning it can be mirrored, on/off function will just be reversed when switching.

@@LifeHarmonic Thank you for the reply, Im all set up and just about to do the soldering. Will let you know how it works out! Im so Amped!

Ok so, its not getting any sound out of it, there is some humming and I can hear the difference when i flip the switch but no music is going thru. Im going to take it to an electrician to see if i soldered everything on right. Hopefully i can get it going, Cheers.

You can use any of those variations, CT versions enable you level control (either step up or down) if you wire it that way, but are not necessary. You could also use a 10k ohm transformer, it is again just not necessary, since output impedance of a sound card is so low. For reamping, "best" cannot be defined in terms of impedances, any of these would work. :) You can use a china made transformer, you just have to check out what is the maximum level you can send low frequencies through before it distorts in an obvious way (this depends on the construction and the core).

This is a good idea, yes 😀

I did the same for my load box. Bronze colour and matte clear on that. Holds well.

Yes, 600 ohm used to be the standard (and for some applications it still is) for matching impedances. When you match the output and input impedance it means that you can transfer the most amount of power over a certain signal path. But we in audio usually don't want to do that, but instead, we want to transfer the most amount of voltage, which means the input impedance should be about 10 times as large as the output impedance. To understand this, you can imagine output impedance as one resistor and input impedance as the second resistor in series and then shunted to ground. With these resistances you create a voltage divider and if the source resistance is very low and the input very high it means that there is very little signal attenuation. If you exclude all the transformers, different impedance matching should normally just have an effect on signal level that you get across. Once you bring in transformers (or in a case of a guitar, an inductive pickup) different impedances also affect frequency response and can affect distortion, depends on how severe you are loading down the source. Dynamic and (passive) ribbon microphones have transformers at their output. And when you load these tranformers down with different impedances, they will change the sound. Why exactly that is, it would require a whole video just on that topic. :) The basic concept is, keep the input impedance at about 10 times the source impedance if you can, this will get you the most transparent sound (especially in the case of a guitar and DI boxes - a lot of DI boxes has, like you said, 30-100k input impedance, which is acceptable when there is a buffered or an active pedal in between a guitar and a DI box, but not when you plug your guitar straight to it (a passive guitar that is, active one is fine). With the volume at 10 your guitar's output impedance is around 10k ohm, with the guitar volume - assuming a logarithmic pot - at about 7-8, its 125-250k ohm, depending on the guitar used. This will severely cut your signal and alter the frequency response, you loose a lot of treble frequencies).

@@LifeHarmonic please do such video 🙂

No, you can use any wire you want. :)

Cool thanks man

Actually, the graph includes phase and frequency response. On the top you can see the frequency response - this one corresponds to the left axis, and on the bottom is the phase response - right axis. If you wanted to tame that ~80kHz spike, you could add a resistor-capacitor network (zobel network) to the secondary of the transformer, but since it's out of the normal hearing range, it's really not necessary. Have a great time building!

@@LifeHarmonic oh. My bad and blindness sorry! Just one thing - would that spike affect anything if using 96k sample rate in daw? Is that connected anyhow? Or doesnt matter at all? And thanks again!

@@myyt4382 Since the highest frequency the 96k sample rate can reproduce is 48khz, there are no issues here. Only at 192khz would this be noticable, but since there is practically zero content in that spectrum coming from any instrument, it's still irelevant.

You are correct, a physically larger transformer handles low frequencies better, but if you are reamping guitar, even detuned, there should be no noticable difference, since the signal is low and doesn't have much bass content. Even with bass guitar the differences would be really hard to notice unless you were really pushing output signal, but since we're trying to replicate what the actual guitar puts out, signal wouldn't normally be that high.This transformer can pass 20-20kHz easily, so there is no cutoff.