ampage Tube Amps / Music Electronics	For current discussions, please visit Music Electronics Forum.

ampage archive

Vintage threads from the first ten years

Am I to dumb(le) to understand this??

5/3/2000 1:16 PM
Dominik	Am I to dumb(le) to understand this?? Hi there, I recently built a Dum-bell-preamp clone. The amp is now working, but I have some problems with channel switching. I use three relays (onefor each channel: Clean/OD) and one to switch between channels: 70s/Skyliner. The switching itself is noiseless due to electrolytic caps across + and - DC on the relays. The only problem is that: I get the 6 V DC from another Heater winding of my tranny (its got two: 6.3 V 2.7 A and 6.3 V 1.5 A, this one is used for the heaters) and I rectify the 6.3 V 2.7 A using a full-wave-bridge. The bridge´s outputs (+ and - 8.5 V) are connected by a 10.000uF electrolytic (16V) paralleld with a 1.5 k resistor. Minus-pole then is grounded through a 180 ohm resistor, as well as the plus-pole. I get about 6.4 V if this circuit is unloaded. But if I connect the relays (winding resistor: 180 Ohms each), plus two LEDs (If 10 mA),the voltage goes down when I switch one relay until it reaches almost 0 Vs when two relays are engaged at once. I have absolutely no idea why that is so. If I use a standard ower-supply from (for example) a portable CD-Player(9V 600 mA), no such thing happens. I would really appreciate if someone could help me with thator enlight me. Thanks for your patience, Yours sincerely, Dominik www.geocities.com/BourbonStreet/Delta/5833

5/3/2000 1:16 PM

Dominik

Am I to dumb(le) to understand this??

Hi there,
I recently built a Dum-bell-preamp clone.
The amp is now working, but I have some problems with channel switching. I use three relays (onefor each channel: Clean/OD) and one to switch between channels: 70s/Skyliner.
The switching itself is noiseless due to electrolytic caps across + and - DC on the
relays. The only problem is that:
I get the 6 V DC from another Heater winding of my tranny (its got two: 6.3 V 2.7 A and 6.3 V 1.5 A, this one is used for the heaters) and I rectify the 6.3 V 2.7 A using a full-wave-bridge. The bridge´s outputs (+ and - 8.5 V) are connected by a 10.000uF electrolytic (16V) paralleld with a 1.5 k resistor. Minus-pole then is grounded through a 180 ohm resistor, as well as the plus-pole. I get about 6.4 V if this circuit is unloaded. But if I connect the relays (winding resistor: 180 Ohms each), plus two LEDs (If 10 mA),the voltage goes down when I switch one relay until it reaches almost 0 Vs when two relays are engaged at once. I have absolutely no idea why that is so. If I use a standard ower-supply from (for example) a portable CD-Player(9V 600 mA), no such thing happens.
I would really appreciate if someone could help me with thator enlight me.

Thanks for your patience,
Yours sincerely,
Dominik
www.geocities.com/BourbonStreet/Delta/5833

Replies:

Don Symes Nothing's getting hot, right? -- 5/3/2000 2:52 PM
Gil Ayan Dominik, here are some points that ... -- 5/3/2000 4:12 PM
Dominik Re: Am I too dumb(le) to understand this?? -- 5/5/2000 12:48 PM