HRP_50
Moderators: pompeiisneaks, Colossal
Re: HRP_50
Hello, does the fx loop work good when coming from the master volume instead of the treble pot into the fx loop then back out to the master volume pot? Ive always wondered.
- maint_tech
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2 others liked this
Re: HRP_50
@PDF64 - 3K2 xfmr, I just thought having the safety resistor on the main spkr out switched pole made sense i case forget to plug spkr in or bad cable.
@ Steveo - I dunno. I have never tried a passive fx loop either way and this is how Mark Fowler did it on the units he built, so that is what I went with. He has said in the past it works well, so I'll find out and report.
@ Steveo - I dunno. I have never tried a passive fx loop either way and this is how Mark Fowler did it on the units he built, so that is what I went with. He has said in the past it works well, so I'll find out and report.
- maint_tech
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Re: HRP_50
Well got the chassis done just in time for a present to myself. Wow, this thing does just grab you by the yaya's! I'll be suffering (more) hearing damage, no doubt. I don't want to change a thing in it, thanks for the encouragement Mark. Yes it is bright, but not ice pick bright, just easy to get out a screecher bright. And if the axe isn't in tune, its gonna let you know it ain't happy!
Damn, more woodwork, gotta build a box.
FX loop works great coming off the Volume, have not tried to relocate it to the treble pot yet, having too much fun.
Presence and depth controls are a treat.
Damn, more woodwork, gotta build a box.
FX loop works great coming off the Volume, have not tried to relocate it to the treble pot yet, having too much fun.
Presence and depth controls are a treat.
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Re: HRP_50
Congrats for your build and merry Christmas: that's something of a present!
Re: HRP_50
Looks great and enjoy that beauty.
Mark
Mark
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Re: HRP_50
Nice build!
Have to ask
What's the Neon bulb on V2 for?
Like Diode clipping?
D
Have to ask
What's the Neon bulb on V2 for?
Like Diode clipping?
D
Re: HRP_50
Very nice build indeed.
When I was watching your pictures I looked like you placed the 100 pF cap on the 220K resistors as per schematic it is placed over the plate resistors off the PI.
With regards,
Auke
When I was watching your pictures I looked like you placed the 100 pF cap on the 220K resistors as per schematic it is placed over the plate resistors off the PI.
With regards,
Auke
Auke
Re: HRP_50
http://www.valvewizard.co.uk/dccf.htmldcribbs1412 wrote: ↑Wed Dec 29, 2021 8:54 pm ...What's the Neon bulb on V2 for?
Like Diode clipping?
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Re: HRP_50
Gottchatmknight wrote: ↑Thu Dec 30, 2021 1:36 pmhttp://www.valvewizard.co.uk/dccf.htmldcribbs1412 wrote: ↑Wed Dec 29, 2021 8:54 pm ...What's the Neon bulb on V2 for?
Like Diode clipping?
I think Jim Kelley used something similar using diodes for "clamping"
musant wrote: ↑Sat Aug 01, 2020 11:47 pm Regarding the diodes, they're really not clippers as much as they're voltage clamps - to keep the grids from going too far negative. That causes a shift in duty cycle at lower frequencies (asymmetrical), gives a flubby, compression-like effect. It's more of a DC thing than an AC thing. A grid stopper is the latter-day method of dealing with the issue.
- martin manning
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Re: HRP_50
The neon bulb or diode/resistor from g to k on a direct-coupled CF is purely a protective measure, not for sound. From the Valve Wizard page linked above:
"...on start up, the grid will immediately rise to HT potential while the cathode is still cold, at ground potential. It is not unknown for this to cause arcing between the electrodes, and rapid destruction of the valve, even when a standby switch is used..."
"...on start up, the grid will immediately rise to HT potential while the cathode is still cold, at ground potential. It is not unknown for this to cause arcing between the electrodes, and rapid destruction of the valve, even when a standby switch is used..."
- maint_tech
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Re: HRP_50
Thanks for all the comments!
Ya the neon glows for a bit when everything is warming up keeps the CF from an early demise. I think this one flashes at about 67 volts or so.
Haven't had any signs of oscillation tho...
Man this thing does wail!
Ya the neon glows for a bit when everything is warming up keeps the CF from an early demise. I think this one flashes at about 67 volts or so.
Ya I gotta move that, thanks. Fixed Skat and layout to reflect in original post.
Haven't had any signs of oscillation tho...
Man this thing does wail!