Hi-Gain SE

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matt h
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Re: Hi-Gain SE

Post by matt h »

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Last edited by matt h on Fri Mar 27, 2015 5:44 am, edited 1 time in total.
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angelodp
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pots

Post by angelodp »

Tubewell, I am running a 250k for the RAW, would the 1 meg pot buy me anything.
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tubeswell
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Re: pots

Post by tubeswell »

angelodp wrote:Tubewell, I am running a 250k for the RAW, would the 1 meg pot buy me anything.
Nah 250k will be fine. 1M will buy more noise
He who dies with the most tubes... wins
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angelodp
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Bias and plate dissipation

Post by angelodp »

Hi I am at 365 plate voltage ( to ground ) 350v ( pin 8-3 ) with a 6v6. I have a 470 ohm cathode resistor.

Voltage drop across the 470 = 24.3

24.3/470 = 51ma

51x365 = 18.6 watts.

51x 350 = 17.8 watts

Thats pretty high for a 6v6.

I am looking at taking the cathode resistor up to 650 ohm - 1k 3watt.

This seems like typical problem with the blackface vibrochamps. Open to any other suggestions. Amp runs and sounds good just that 6V6 is hot.

Best A

I added a 470 ohm in series with the other cathode 470 ohm for 940 ohm total - 360 plate voltage pin 3-8

Gives me 31ma for 11.1 watts dissipation. Sounds much the same but is running cooler for sure.
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angelodp
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Added a LOOP

Post by angelodp »

I Added a loop from the Master to power tube grid, works great. Now this little champ has even more functionality.

[IMG:1024:834]http://i260.photobucket.com/albums/ii9/angelodp1/565-redo-pin-swap-boostMV-2-Wloop_zps2e81479a.jpg[/img]
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Cantplay
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Re: Hi-Gain SE

Post by Cantplay »

Why did you choose tube rectifier over diodes on a single ended amp?

John
Do not limit yourself to what others think is reasonable or possible.

www.johnchristou.com
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angelodp
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Champ origin

Post by angelodp »

I started with a Champ like design and kept with the tube rectifier approach. I may try solid state rectification on another similar amp soon. These amps are created from donor amps that were used in editing systems and employed tube rectifiers.
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angelodp
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some additions

Post by angelodp »

I have added two voltage dividers at the V1a&b plates. This has helped with the gain structure. I now have a loop to accept my recent S/P Dlator and I added a bright switch. Gotta say this little amp does rock. Still running 12AX7 in V1 and 5751 In V2.

[IMG:1024:834]http://i260.photobucket.com/albums/ii9/angelodp1/565-redo-pin-swap-boostMV-2-Wloop-Voldiv3_zps8341d096.jpg[/img]
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angelodp
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Its cold out here

Post by angelodp »

Is that the line from SRV….

So I popped in a 6l6 also upped the cathode R on V2B to 4.7k. Very nice… more bottom clarity and power is up as well. Headroom improved.

All good…. thanks Dave.
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