Amp Tech Thread / Ask a tech Q

[VOLVO)))]

Amp attached to speaker cab but amp not plugged into wall, turn on both switches for 15 minutes, speakers should drain caps.  This is prolly the least intrusive way but just to be sure I use a meter set to 1000vdc.  There's always just the screwdriver method.

I've practically welded a screwdriver to an SVT chassis before.

[Mr. Foxen]

I made up a discharge tool that is crocodile clips on a resistor around 20k or so, clip that on the relevant place and sorted.

[dunwichamps]

Amp attached to speaker cab but amp not plugged into wall, turn on both switches for 15 minutes, speakers should drain caps.  This is prolly the least intrusive way but just to be sure I use a meter set to 1000vdc.  There's always just the screwdriver method.

speakers wont drain the power supply, they are electrically isolated from the amp via the OT. The only way the power supply is going to drain over time is to have a resistive path from one of the supply caps to ground.

[RacerX]

Check this crazy new tuner out! Pretty rad:

http://techcrunch.com/2013/11/20/you-can-tune-a-guitar-but-you-cant-tune-a-fish-with-roadie/

[Mr. Foxen]

Check this crazy new tuner out! Pretty rad:

http://techcrunch.com/2013/11/20/you-can-tune-a-guitar-but-you-cant-tune-a-fish-with-roadie/

Knowing which way to turn the machine head is something I can understand needing a device to tell you. The actual turning it part, not so much.

[FullCustom]

I'm not down with anything that requires an iProduct to operate.

[Boguspierre80]

Hi:



I'm researching Sleep from back in the 90s and am curious as to what a Matamp Slave unit is used to perform. Amplify the amplifier? I've performed a search of the jam room and poked around Google. Nothing seems to be explained out too well regarding these slave units for the newby's understanding.

B

[VOLVO)))]

It's just a power section. Basically the amp, minus a preamp.

[Mr. Foxen]

Yeah, its just what they called power amps before people lost the ability to understand context before they got offended.

[RAGER]

It's all shrouded in mystery.

[VOLVO)))]

Yeah, its just what they called power amps before people lost the ability to understand context before they got offended.

You're sassy tonight.

[Jake]

Tonight?

[moose23]

You "slave" the slave unit off the "master" or preliminary amplifier's pre amp stage so you get essentially the same pre amp sounds going to more than one power section and their respective cabinets.

Also google skills are extremely lacking as I found pages of links when I searched "slave amp".

http://www.seymourduncan.com/blog/tips-and-tricks/obey-your-master-the-art-of-amp-slaving/

[Boguspierre80]

I Googled "Slave Unit" and not "Slave Amp" as that's what's on the picture I provided.  That probably explains the disparity. Thanks for that link, by the way. I'm starting to maybe slave my Blackstar HT 20 to the Orange OR15 head. It would be cool to hear that particular preamp stage through the EL34s of the Blackstar. Both amps have effects loops.

[VOLVO)))]

Nobody thought It was funny when I called my slave amp "N-word Marshall"

[Boguspierre80]

Nobody thought It was funny when I called my slave amp "N-word Marshall"

I guffawed.

[Boguspierre80]

Alright, so after reading up, I understand that I can take my Orange's FX send and route that to the Blackstar's FX return. The master amp (Orange) will still need a speaker load, right? If I don't have an extra cab, can I just remove the EL84 power amp tubes? Am I still demonstrating no grasp of this topic?

[Jake]

You do not want to do that.

[Mr. Foxen]

You can probably run the other amp with no power valves, not much bad can happen, but without the current draw from them, possibly some odd stuff can happen, voltages not being quite right and such, generally that would only upset power valves though.

[Boguspierre80]

Thanks for the advice. I'll put a LOT more study into this subject and perhaps befriend an electrical engineer before ever attempting to cascade amps. Back to the drawing board.

[VOLVO)))]

Cheap Peavey cab, go ahead, they're on Craigslist... W

[Mr. Foxen]

Thanks for the advice. I'll put a LOT more study into this subject and perhaps befriend an electrical engineer before ever attempting to cascade amps. Back to the drawing board.

Current electrical engineers might have no clue about the function of valves amps though. There was a Klipp on ebay that had been got to by a current electrical engineering student and they utterly fucked it.

[dogfood]

http://www.mojotone.com/guitar-parts/Guitar-Capacitors/Volume-Mod-for-Guitars#.Utv7SGcanIX

are the cap and resistor bi directional?

[VOLVO)))]

wee ceramic caps aren't polarized.

[dunwichamps]

if its a slave then its just the input of the phase inverter of a GT120 with a volume pot on the input to control the volume. Simple as that