Real-Deal Pres/Feed Ckt

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bluesfendermanblues
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Re: Real-Deal Pres/Feed Ckt

Post by bluesfendermanblues »

UltraHookedOnPhonix wrote:Thanks Dogears!

So I guess it is safe to assume that there's 50W amps out there that are running the standard PI values from the 100W version (that's what they are doing in half power mode anyways!)

I'm going to simply replace the 1K/8.2K that I have in there now for 390R/4.7K and see what happens.
a) Damping on 1k/8.2k combination = 8.2/1 = 8.2
b) Damping on 390/4.7k combination = 4700/390 = 12

'b' is 1.5 times "looser" in the damping of the speaker(s) than 'a'
You could also replace the 4.7k with a 22k or 10k trim and tune the damping to your liking. Running the amp flat out, the amp the amp looses its ability to controll the speaker movements.
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heisthl
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Re: Real-Deal Pres/Feed Ckt

Post by heisthl »

Color me stupid because I'm too lazy to search the forum, but I thought the 8k2/1000 was used on the 8 ohm tap in the one known 50 watt real example. And now my real question - what if you only have a 2OHM tap? 2k7/200? 2k2/180?
Former owner of Music Mechanix
www.RedPlateAmps.com
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Structo
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Re: Real-Deal Pres/Feed Ckt

Post by Structo »

Do you have the jumper on the bass pot?
I had the same issue using mainly strats and teles and once I removed that jumper it became more controllable with the bass pot.
Tom

Don't let that smoke out!
bluesfendermanblues
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Re: Real-Deal Pres/Feed Ckt

Post by bluesfendermanblues »

heisthl wrote:Color me stupid because I'm too lazy to search the forum, but I thought the 8k2/1000 was used on the 8 ohm tap in the one known 50 watt real example. And now my real question - what if you only have a 2OHM tap? 2k7/200? 2k2/180?
Choice of OT tap is not critical at all IMHO
dogears
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Re: Real-Deal Pres/Feed Ckt

Post by dogears »

Dude, that is not correct. The choice of what tap to take the negative feedback off of is super critical. The 8 ohm tap has 40% more voltage on it than the 4 ohm tap.

The choice of what tap you choose to plug into, as in 4 ohm cabinet or 8 ohm cabinent, is of much lesser importance.

We are referring to the inside of the amp.
bluesfendermanblues wrote:
heisthl wrote:Color me stupid because I'm too lazy to search the forum, but I thought the 8k2/1000 was used on the 8 ohm tap in the one known 50 watt real example. And now my real question - what if you only have a 2OHM tap? 2k7/200? 2k2/180?
Choice of OT tap is not critical at all IMHO
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jelle
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Re: Real-Deal Pres/Feed Ckt

Post by jelle »

dogears wrote:Dude, that is not correct. The choice of what tap to take the negative feedback off of is super critical. The 8 ohm tap has 40% more voltage on it than the 4 ohm tap.

The choice of what tap you choose to plug into, as in 4 ohm cabinet or 8 ohm cabinent, is of much lesser importance.

We are referring to the inside of the amp.
bluesfendermanblues wrote:
heisthl wrote:Color me stupid because I'm too lazy to search the forum, but I thought the 8k2/1000 was used on the 8 ohm tap in the one known 50 watt real example. And now my real question - what if you only have a 2OHM tap? 2k7/200? 2k2/180?
Choice of OT tap is not critical at all IMHO
Now you know where these ratio's come from...

Damping on 1k/8.2k combination = 8.2/1 = 8.2
Damping on 390/4.7k combination = 4700/390 = 12
:idea: :D

Have fun!

Jelle
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