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Topics - mattilla

#1
Hi, please forgive this largish post, but I've been wracking my brains with this. I have 2 Jensen Mod speakers in a homemade cab, both rated 25W @ 8 ohms. What I would like is to be able to wire them up so that I can toggle between 4, 8 and 16 ohms. Obviously, 4 ohms would require the speakers to be in parallel, 16 ohms in series, and 8 ohms would just use one of the speakers directly. I know there are wiring diagrams around that already clearly explain how to wire up 2 x 8 ohm speakers for 4 and 16 ohms selectable output. But adding the extra 8 ohm option does my head in!  :duh

I've broken it down & I "think" I have arrived at a solution, but could some of you more knowledgeable amp techies please have a look?

Here are the 3  different wiring options (for 4, 8 & 16 ohms) --



And here's the solution (?) I came up with. I "think" it would work, however, it requires 2 toggle switches to route the signal path appropriately --



Here it is again with the 4, 8 & 16-ohm signal paths traced out in different colours to avoid (??) confusion of where I'm going with this ---



What I plan is a metal plate on the back of the cab with a couple of toggle switches and of course the mono input socket, something like this --



I "think" this is a viable solution, but to be honest I don't like the two toggle switches - it looks a bit awkward & ugly. Also you would have to be very careful to have the switches toggled correctly. But is this the only way to do this, do you think? Does anyone have any suggestions or ideas around this?

Thanks in advance.
#2
This might seem a dumb question... I'm building a Tiny Giant amp into a simple cab (an upside down Ikea "Rast", see pic!), with a couple of Jensen Mod 8" speakers... The space at the top of the Rast is exactly 2RU 19" rack panel size. I can mount knobs etc onto the rack panel with the Tiny Giant PCB behind it... My question is, does the amp PCB require an aluminium enclosure to shield against RF/hum etc? In which case, can I still have wires coming out of the enclosure to connect with the pots & switch etc on the front rack panel?

My confusion comes from seeing some DIY amps fully enclosed, others half-enclosed, others not at all, etc etc...?

I hope I'm making sense here lol.

(Rast unit below - imagine it upside down!)
#3
Amplifier Discussion / FS Audio FG212DSP guitar combo??
November 21, 2013, 10:16:14 PM
Has anybody heard of this Chinese brand?

http://www.vfmaudio.com.au/product.php?id_product=332

For a 250W combo it is very cheap!? Piece of *s!!t* you reckon?