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Post subject: Need more headroom w/silverface 74 deluxe reverb
Posted: Wed Feb 04, 2009 8:06 pm
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I just traded a 90's Marshall 2 12 50-100 watt combo that weighed a ton for this 74 silverface DR. I bought a new one in 1971 and I remember it broke up around 6 or 7. This has the Weber 12 that is recommended by Weber for the Deluxe Reverb and the caps have been replaced(I have the old ones) and the tubes were replaced with JJs and they appear to be a blackface replacements because there are no 12at7s just 12ax7s all the way down to the power tubes 6v6s then the last in line is a GZ 34 S(i think) having trouble in dim light and my bad handwriting. I thought and was told the closest tube to the 6v6s was the Phase Inverter which should be a 12at7 but it's a 12ax7. Also this reliable source told me that might raise the headroom and its a common practice to get more distortion. Which isn't what I want, so my question is if I change the phase inverter 12ax7 to the specs 12at7 will I gain more of a clean sound. Thanx for any help I can get. Next step is a rebias! Philvis


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Fender Play Winter Sale 2020
Post subject:
Posted: Fri Feb 06, 2009 7:18 pm
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Joined: Mon Jul 16, 2007 6:51 pm
Posts: 25350
Location: Witness Protection Program
Check out the Eminence Swamp Thang.

SWAMP THANG™
SPECIFICATION
Nominal Basket Diameter 12 , 304.8mm
Nominal Impedance* 8 ohms
Power Rating
Watts 150W
Music Program
Resonance 97Hz
Usable Frequency Range 70Hz-5kHz
Sensitivity*** 102
Magnet Weight 59 oz.
Gap Height 0.312 , 7.92mm
Voice Coil Diameter 2 , 50.8mm

THIELE & SMALL PARAMETERS
Resonant Frequency (fs) 97Hz
DC Resistance (Re) 6.92
Coil Inductance (Le) 0.42mH
Mechanical Q (Qms) 14.43
Electromagnetic Q (Qes) 0.55
Total Q (Qts) 0.53
Compliance Equivalent Volume (Vas) 41.3 liters / 1.5 cu. ft.
Peak Diaphragm Displacement Volume (Vd) 43cc
Mechanical Compliance of Suspension (Cms) 0.10mm/N
BL Product (BL) 14.2 T-M
Diaphram Mass inc. Airload (Mms) 26 grams
Efficiency Bandwidth Product (EBP) 177
Maximum Linear Excursion (Xmax) 0.8mm
Surface Area of Cone (Sd) 532.4 cm2
Maximum Mechanical Limit (Xlim)

MOUNTING INFORMATION
Recommended Enclosure
Sealed Acceptable
Vented Acceptable
Overall Diameter 12.01 , 305.1mm
Baffle Hole Diameter 10.95 , 278.1mm
Front Sealing Gasket fitted as standard
Rear Sealing Gasket fitted as standard
Mounting Holes Diameter 0.25 , 6.4mm
Mounting Holes B.C. D. 11.63 , 295.4mm
Depth 5.2 , 132mm
Net Weight 11.1 lbs., 5 kg
Shipping Weight 12.8 lbs., 5.8 kg

MATERIALS OF CONSTRUCTION
Coil Construction Copper voice coil
Coil Former Polyimide former
Magnet Composition Ferrite magnet
Core Details Non-vented core
Basket Materials Pressed steel basket
Cone Composition Paper Cone
Cone Edge Composition Paper cone edge
Dustcap Composition Zurette dust cap

_________________
Being able to play and enjoy music is a gift that's often taken for granted.

Don't leave home without it!


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Post subject: is a speaker swap what I'm hearing!
Posted: Fri Feb 06, 2009 7:34 pm
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I've done some reseating on the tubes cause they were basically new when I got the amp and tightened down the ground screws, low and behold this amp is starting to sound like the new one I got in 1971, so a speaker switch to this "Swamp Thing" although expensive could give me what this Weber don't. I'll check it out thanks.


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