An "Omage" to Harvey Gerst - D130 Question

[jcrobso]

Okay...I found a schematic for the 1484. It certainly doesn't produce 100 watts (so no problem there) with only 2 6L6GC's and there is no overall loop feedback from the secondary. As well there is only one output tap on the transformer...I'd go with he 8 ohm D130 and input level attenuators.

The two Jensen speakers are 8 ohm giving a 4 Ohm load.
The schematic shows +475 volts on the plate, this could give you a max of about 50watts RMS. As others have stated for maximum power transfer the load should be the same as the output impedance of the transformer. I don't feel that 16 Ohms should be problem. You could get 8 Ohm 100w L pad then the amp would see 8 Ohms and you can reduce the level and run amp up in the range where it sounds good. John

[sba2]

Hi, I've been searching this site for the T-S parameters on the JBL d130f, but have not had any luck. I'd appreciate any help. Thanks

[SMKSoundPro]

JBL PROFESSIONAL
THIELE SMALL LOW FREQUENCY DRIVER
PARAMETERS AND DEFINITIONS
April 2, 2005
Page 4 of 5
MODEL FS QTS QMS QES VAS EFF PE XMAX RE LE SD BI MMS FLUX
D130 40 0.25 4 0.27 297.3 6.7 75 0.76 6.3 0.6 0.090 18 60 1.2

[SMKSoundPro]

JBL PROFESSIONAL

THIELE SMALL LOW FREQUENCY DRIVER
PARAMETERS AND DEFINITIONS

April 2, 2005
Page 4 of 5

MODEL FS QTS QMS QES VAS EFF PE XMAX RE LE SD BI MMS FLUX
2231H 16 0.21 5.5 0.22 736.2 1.4 100 5.08 6.3 1.4 0.088 21 151 1.2
2234H 23 0.22 2 0.25 458.7 2.1 150 8.38 6 1.2 0.090 20.5 105 1.2
2235H 20 0.25 2.5 0.28 458.7 1.3 150 8.38 6 1.2 0.090 20.5 155 1.2
2240G 30 0.25 2.5 0.25 481.4 5 300 5.59 2.5 0.7 0.130 17.1 164 1.22
2240H 30 0.23 2.2 25 481.4 5 300 5.59 6 1.4 0.130 25 164 1.22
2241G 35 0.4 5.7 0.43 311.5 2.9 600 7.62 2.5 0.86 0.123 13.6 145
2241H 35 0.4 5.7 0.43 311.5 2.9 600 7.62 5 1.75 0.123 19.2 145
2242H 35 0.28 5 0.29 282.3 4 800 7.87 4.7 1.25 0.124 23.7 158
2245H 20 0.27 2.2 0.27 821.2 2.1 300 9.65 5.8 1.4 0.130 21 185 1.22
2250H 188 0.47 4.5 0.53 1.67 2 350 3 5.2 1 0.0204 17 25 1.0
2250J 185 0.45 4.8 0.47 1.5 2.3 350 3.0 8.7 1.7 0.0204 22.5 24 1
2251J 61 0.2 4 0.21 1.011 2.89 388 5.7 12.65 0.031 26.77 0.032
2254J 46.63 0.16 2.47 0.17 2.60 4.20 600 6.35 11.16 0.063 10.99 0.088
2255H 39 0.30 3.68 0.33 170 2.9 650 8 5.0 1.5 0.088 20.1 109
2256G 24.2 0.47 7.79 0.5 138.5 600 20.3 3.1 0.7 0.078 15.7 284
2258H 31 0.27 4.82 0.28 407 800 8 5.2 1.24 0.124 22.3 140
2262H 56.2 0.34790.39 42.2 2.2 700 8 5.2 0.055 18 68.0
2265H 37 0.32 3.3 0.36 176 2.5 750 8 5.1 1.7 0.088 19.5 112 0.6
2266H 31 0.37 4.8 0.4 110 0.8 700 11 4.8 2.63 0.088 24.7 260 0.6
2268H 33 0.36 3.8 0.39 328 2.8 800 23 5.3 1.85 0.1269 21.5 168 0.6
D123 45 0.45 4.5 0.5 135.9 2.5 50 2.54 6 0.5 0.053 12.4 45 1
D130 40 0.25 4 0.27 297.3 6.7 75 0.76 6.3 0.6 0.090 18 60 1.2
D131 50 0.18 8.5 0.18 127.4 8.4 75 0.76 6.3 0.5 0.053 18 35 1.2
D208 60 0.31 3.5 0.34 34.0 2.1 25 2.54 6 0.3 0.021 6.8 11 0.85
E110 65 0.36 4 0.4 45.3 3 75 2.54 6 0.4 0.032 12.1 21 1.03
E120 60 0.17 1.8 0.19 79.3 8.6 150 3.05 6.3 0.4 0.053 21.7 36 1.35
E130 40 0.19 1.8 0.21 297.3 8.6 150 2.54 6.3 0.4 0.090 21.1 60 1.35
E140 32 0.17 5 0.19 297.3 4.9 200 3.56 5.5 1.11 0.090 24.1 94 1.35
E145 35 0.25 6 0.26 274.7 4.3 150 7.11 5.7 1.6 0.090 16.1 55 0.97
E155-4 30 0.2 2.2 0.22 424.8 4.9 300 5.08 2.5 0.7 0.114 17 125 1.22
E155-8 30 0.2 2.2 0.22 424.8 4.9 300 5.08 6 1.4 0.114 25 125 1.22
G125-8 65 0.32 5.5 0.34 70.8 5.5 200 2.54 5.2 0.5 0.053 13.7 37 0.98
G135-8 45 0.36 5.5 0.38 235.0 5.5 200 2.54 5.2 0.5 0.090 13.7 60 0.98
G135-A 45 0.48 6.6 0.51 218.0 3.8 200 6.10 6 0.75 0.090 15.8 60 0.98
K110 65 0.36 4 0.4 45.3 3 75 1.52 6 0.4 0.032 10.3 17 1.02
K120 50 0.2 4 0.21 121.8 6.9 100 1.52 6.3 0.6 0.053 18 35 1.2
K130 40 0.25 4 0.27 297.3 6.7 125 0.76 6.3 0.6 0.090 18 60 1.2
K140 30 0.21 5 0.22 297.3 3.5 150 5.08 5.5 1.3 0.090 22.3 105 1.2
K145 35 0.29 6 0.3 243.5 3.4 150 5.08 8.8 2.2 0.079 21.7 75 0.9
K151 30 0.27 6 0.28 365.3 3.4 150 2.54 6 2 0.107 22 125 1.2
LE5-10 250 1 3 1.6 0.7 0.69 25 1.52 6 0.05 0.006 4.3 3 1.3
LE8T 45 0.49 4 0.55 34.0 0.5 25 4.57 5.5 0.3 0.018 6.2 16 0.85
LE8TH 45 0.56 4 0.65 34.0 0.5 25 5.59 5.5 0.3 0.018 6.2 16 0.85
LE10A 30 0.41 6 0.44 101.9 0.6 75 6.10 4.4 0.6 0.032 8.1 35 1.02
MODEL FS QTS QMS QES VAS EFF PE XMAX RE LE SD BI MMS FLUX

88

[sba2]

SMKSoundPro, Thank you very much for posting the T-S parameters.