[Dirk]

Hi !

In fact the documentation and product descriptions needs an update and we will do this asap.

BUT even with a step-by-step instruction the risk is very high because the customer does righten know how to check the security of his build nor how to trace and solve problems in case the amp is not working.

@Sepp: Danke Dir für die Übersetzung. Die darf ich so übernehmen und muss mir die Arbeit nicht selbst machen ?

Gruß, Dirk

[kugelblitz]

You may take it as is or even better, maybe Steven can provide a better translation. Mine is no translation but my thought on how to avoid this situation. Fell free to take it.

 @step-to-step instructions: Thats the reason why i mentioned "information a service technican would need to ...". This line includes, at least from my point of view, the postulate the buyer/builder/user has to have knowledge...

BR,
Sepp

[shto]

Hi !

In fact the documentation and product descriptions needs an update and we will do this asap.

I appreciate that, there's a huge amount of information on this site, it must be a lot of work keeping it updated. However, you can understand my frustration - I now have a half-built kit, and no idea how to proceed, and now, a week after I ordered it, I'm being told I shouldn't have bought it since I'm not a trained electrical engineer. If any other users on this forum have a completed Reverb kit, I'd really appreciate some photos, or useful information. Much as I'd love to train as an electrical engineer, it's not likely to happen any time soon. I do take your points about completing the project safely, and having the ability to troubleshoot, but Madamp, Ampmaker, Triode, and several other sites include all this information, and are happy to help with email support. I don't understand why it's such a problem here.

[current]

Please find attached two pictures of the primary wiring on my TT Reverb kit.

There are three connectors on the mains socket. As already mentioned, the most important connection to make is the PE (yellow&green wire). This should go to chassis, using the hole drilled closed to the mains socket. Note that I left this wire quite a bit longer than the connection to the mains switch.

The other two connections (blue and black wires) go to the mains switch. Use the middle lugs on the switch.

Connect both the pilot light and the primary side of the transformer to the mains switch. Use the top two lugs for this. You can see I used the yellow wires for the pilot light and the black ("0") and red ("240V") wires from the PT.

You will have to select the correct wall voltage on the primary side of the transformer. This will leave you with two unused wires - cut them and insulate their ends, e.g. with heat shrinking tube. A good way to check the selected wall voltage is to check the heater voltage later on, this should be 6.3V +/- 10%. In my build, I get 6.6V AC.

On the secondary side, the green wires should go to the valve heaters. The red wires should go to the power supply - but connect one of them to the HT Fuse!

If you have built other amp kits before, please look at their schematics and try to match them with what you have here - it really should not be that different. Please also look at this web site: http://www.valvewizard.co.uk/fuses.html. There are two schematics which show the exact wiring used in this kit.

Also, I would strongly suggest to have your wiring checked by a person with a background in electronics! Citing the "Valve Wizard" site:

Building and modifying amplifiers is DANGEROUS (like most fun things). Valve amplifiers invariably contain both very high voltages and high currents, capable of killing you. ... It is up to you to exercise caution and common sense at all times to avoid electrocuting yourself, and make your amplifiers safe to use. I am not responsible for your negligence.

[Han die Blume]

Hi, in this thread several people have given you the needed information and on this page are the photos you are looking for with again all the needed information in it:
https://www.tube-town.net/cms/?DIY/LoW-Projekte/Reverb
You only need to know how to isolate unused wire ends - which you should know after building two reverbs..

Kai

[sjhusting]

The other two connections (blue and black wires) go to the mains switch. Use the middle lugs on the switch.

This makes the two unused lugs live when the amp is switched off. I prefer to connect the mains to the 'on' side of the switch when using a DPDT and go out the middle lugs. And paranoia leads me to shrink -wrap the unused lugs, just in case something unexpected happens. But usually I just use a DPST switch. Just to confuse things.

Pay attention to the markings on the back side of the IEC socket. The lug that goes through the built-in fuse is 'live' and should be connected to the 230/240 volt wire. The other 'N'eutral is connected to the black 0 volt lead (through the switch of course).

Making the yellow and green wire for the PE longer than the others ensures that when your drunk drummer trips over the power cable, ripping the IEC out of the hole, that the connection to ground is the last connection broken. The wire should be longer than any other wire connected to the IEC and it should be free to unwrap and come out the hole.

Steven
 

[shto]

@current - thanks very much, really helpful info - I will, of course, have the work checked out before I connect to the mains. Cheers

[brjernej]

Hallo!
As you are answering in english here, I have few (may be pretty stupid) questions myself (I am thinking about building my own Reverb with the schematic given):
- If the needed voltage for the project is close to the mains voltage - let's say 250V, which is close to our mains 230V - why not omit the transformer and connect the PSU directly to the mains (maybe through a noise surrpresor, if the neighbour is using the power drill). PT is one of the biggest and most expensive components of the project, what is the problem there? Is this trafo only used as an "isolation transformer" really? Or what is the point of the trafo in such circuit? I was thinking about this with another project, I am planning on constructing the Alembic. Surely I need the trafo for the filaments /heaters, but why for the line? Is it the safety issue described here: http://www.instructables.com/id/Isolation-transformer-upgrade-for-old-guitar-amps/ It doesn't look like. AC goes through the fuse directly to the diode bridge - and is nowhere connected to the ground - how could it come to the chassis in those cases? Only maybe with half waveor tube rectification ...
- If I use the trafo with the PSU from the site - which trafo to use? What is the required voltage of the trafo? As I see the "suggestions" on the PSU page, there are 30VA and 50VA toroids, but one has 200V and the other 250V primary - which to use - or it doesn't really matter?
- there is a possibility given on the PSU page to use the choke - which is the correct choke for the PSU to use - and then you omit R3, if I understand correctly. 
- on the cathode bypass capacitors (C2, C6, C7) in the Reverb schematic there are no voltages given - other schematics on net use 25V, but I am not sure. Measured voltages in the schematic seem much smaller, so  (because smaller voltage generally means smaller ESR and size / inductance) would it be better to use a lower voltage caps? Is 6,3V enough? Would you expect a noticable improvement in sound if using poly caps instead of elkos (C2 and C6).
- on the PSU (if I buy just the printed board and then components separately): would it be very messy to use F+T caps (they are axial and have a biiiig diameter)? What about using the can caps? Is there any noticeable improvement when using such better caps? Or is the exact purpose of that PSU that it is not so component-critical (because there is really a lot of them caps there, in the schematics of the same reverb on the net there are four 20/450 or three 40/450 and that's it)
Thank you for your kind answer.

[Dirk]

Hi,

just order the kit and you are happy because it comes with all items that you need to build the reverb.

Best regards, Dirk

[soderstrom]

- If the needed voltage for the project is close to the mains voltage - let's say 250V, which is close to our mains 230V - why not omit the transformer and connect the PSU directly to the mains (maybe through a noise surrpresor, if the neighbour is using the power drill). PT is one of the biggest and most expensive components of the project, what is the problem there? Is this trafo only used as an "isolation transformer" really? Or what is the point of the trafo in such circuit? I was thinking about this with another project, I am planning on constructing the Alembic. Surely I need the trafo for the filaments /heaters, but why for the line? Is it the safety issue described here: http://www.instructables.com/id/Isolation-transformer-upgrade-for-old-guitar-amps/ It doesn't look like. AC goes through the fuse directly to the diode bridge - and is nowhere connected to the ground - how could it come to the chassis in those cases?

OMG, don't kill yourself! Never, ever connect your PSU directly to the mains! This would be really dangerous and stupid! Do yourself a favor and start with some low voltage projects and read some books. You are not ready for voltages above 50 Volts!

[brjernej]

I have made some Low Voltage projects and there are some books about Electronics waiting for me to read.
Scio mihi nihil scire - that is why I asked ... Is it really so hard to explain? Strike me with highly theoretical gibberish, just don't mock me for not knowing.
So, in short: what is the problem? I understand trafo is only a inductance based voltage transforming block and not some guardian angel ...

[_peter]

Hello,

http://en.wikipedia.org/wiki/Galvanic_isolation#Applications

Gruß, Peter

[brjernej]

Thank you! That is the answer I wanted. It would take some time to understand, but it's a starter ...

[brjernej]

first thing: does this "galvanic isolation work if the earthing from the socket is connected to the ground of the device (it is common, there are really scarce devices with some kind of separation, usually through cap and resistor,  betwen "yellow-green" and "black" zone ...)

[Dirk]

I think this has nothing to do with the Reverb Unit and it might be better to start a new thread in the "Beginners" section.

BR, Dirk