[regal]

Quote:

Originally Posted by ujamerstand /img/forum/go_quote.gif I've considered using the Rcore before. But, well, one of the things I want to do in my particular build is that I want to do the regal mod. Also, I want to have enough current to go around regardless of the tube type I use. This is why I wanted to use the Current multiplier power supply mod. The Rcore seems to need a choke supply, and I am not sure whether that power supply mod will be able to supply as much current as the CMPS. That, coupled with the fact that a) having a choke takes up more space, b) the Rcore listed on vt4c's audio catalog is too fat and wide for the enclosure I have in mind, c) As good as vt4c's customer service is, their shipping is a bit on the expensive side, and takes a long time to arrive; means that I am probably going to stick with Hammond transformers. But thanks for the suggestion, I think I'll go with 370DAX for the assurance of less buzz.

I considered the R-core so I could use 8416 tubes but found that since they have been discovered they are just as expensive as their equivalent Amperex 6DJ8's. R-cores also have the disadvantage of passing more HF junk from the power company than the Hammond, I think you are making the right decision.

 

[Olli1324]

Is there a minimum distance the rectifier tube should be from the others? Also, does it matter how close the PCBs are? Am I likely to experience any hum/noise if the amp boards are relatively close to the PS board?

I started drawing/marking up my case for drilling. The tube layout I'm going for is not dissimilar to Balderon's (although I don't think it will trump his for looks).

I will also be damned if I know what I'm going to do with the transformer; only time will tell if it will fit in the case, let alone not cause hum. Are sticking it on the back (outside of the case) or in a little box with an umbilical chord (although that will look less neat) viable options?

 

[ujamerstand]

Eh, since you have everything running, why don't you just play around with the layout to see which one gives the least amount of hum?

Sticking the transformers out the back could work, but then you'll need to take care of all the wires that will need to be connected from the transformer box to the amp. Something like amphenol connector or 8 pole neutrik SpeakON could work? Personally, that's a lot of hassle to deal with, I'd want to avoid that!

Edit: Actually, instead of putting the transformer in a separate box, you can always mount it on top of the enclosure. No need for an extra box, less cords to deal with, Its a better idea overall I think.

 

[Olli1324]

I was asking because I am doing the case in my grandad's workshop and the electronics stuff at my dad's little electronic 'workshop'.

I will continue to mark up the case ( but hold off on the drilling) today, and then tomorrow I should finish the electronics aspect. So after that, I will be able to lay it all out and see if I get any hum/noise.

Which reminds me.. I better get in a pair of HD650s soon...

 

[DemonicAngelz]

I'm not good at electronics so I'm just going to throw this stupid question out. Does the wattage of resistors matter? I have access to relatively reasonable priced kiwame resistors. Was wondering if I can use them to replace those in the amp.

 

[Volkum]

Quote:

Originally Posted by DemonicAngelz /img/forum/go_quote.gif I'm not good at electronics so I'm just going to throw this stupid question out. Does the wattage of resistors matter? I have access to relatively reasonable priced kiwame resistors. Was wondering if I can use them to replace those in the amp.

I wouldn't recommend going under what the project calls for as they could burn out if you run them over spec, but going over on the recommended wattage rating won't hurt (but they may not fit on the board).

 

[DemonicAngelz]

Quote:

Originally Posted by Volkum /img/forum/go_quote.gif I wouldn't recommend going under what the project calls for as they could burn out if you run them over spec, but going over on the recommended wattage rating won't hurt (but they may not fit on the board).

Thats what I thought. Kiwame only comes in 2W and 5W types..

As for fitting on the board, they will not fit flush but should vertically. The bijou board aint really stingy on space given.

 

[Olli1324]

Are you sure the leads will fit? I can't get my spare 1/2 watt resistors to fit through the holes; only the 1/8th watt has leads thin enough to fit.

 

[adamus]

I used a couple of kiwames when i regal modded the bijou, and it was tighter than a....

 

[bhjazz]

Quote:

Originally Posted by Volkum /img/forum/go_quote.gif I wouldn't recommend going under what the project calls for as they could burn out if you run them over spec, but going over on the recommended wattage rating won't hurt (but they may not fit on the board).

Exactly. If your resistor is at or above what is in the schematic, it will do fine. You can throw a lot of cash at resistors that are overspecced, so unless it's a great deal, you probably won't need to.
In the range that the Bijou calls for, you can certainly use some of "the good stuff": Vishay, Holco, etc.

 

[Olli1324]

What's that I hear? ...Oh, it's a Bijou!

Electronics all a-ok.

I will start drilling the case Monday/Tuesday/whenever I have the afternoon off.

And, dammit, I missed a good deal on HD650s this evening..

 

[ujamerstand]

Good deals on HD650s comes every 2 days or so on headfi.

Actually, its the first set of headphone I bought on headfi.

 

[bhjazz]

Quote:

Originally Posted by Olli1324 /img/forum/go_quote.gif What's that I hear? ...Oh, it's a Bijou! Electronics all a-ok. I will start drilling the case Monday/Tuesday/whenever I have the afternoon off.

Fantastic! Wow, you really cruised through that. Have fun!

 

[metreonfuture]

hey, is it really that dangerous to build this amp? how so? (there's a warning on the glass jar site).

and how much would it cost to do a 10milliamp version of this The Bijou Headphone Amplifier (price range?)

 

[ujamerstand]

In the worst case scenario you can kill yourself, or leave a nasty burn. It is not a safe toy to play with. It contains high voltage and must be treated with respect.

Regal mod involves changing a couple of resistors. If you have an electronics parts shop in your area, I don't think it should cost over 5 dollars. If not, the resistors can be bought online. Digikey offers $8 dollars shipping. (next day? I think?). If you cannot regulate the power supply to 250V, ECC99 tubes can be found on the net, a new JJ ECC99 tube costs around 15- 17 dollars I think? Look around, they should be easy to find.