Output Transformers, EIA codes, tubes and hot-rodding.

[Russ]

If you are a proud owner of a Bass 400 than you may be aware that at
originally these amps shipped with 6550 power tubes. Sometime in the
80's Mesa switched over to 6L6GC tubes for this amp. The 6L6GC puts
out a lot less watts than a 6550. It is fair to say roughly half as
many watts. However the Bass 400 when it ran 6550's was very
conservative. Instead of the 700v you would see on a 6550 in an SVT
the Mesa amp only supplies 526 volts. Instead of 300 watts we should
see 200 watts in theory. Some folks have tested out these amps and
seen about 180-190 watts, which would be in line with the cold bias
that Mesa amps often use.
I am investigating the practicality of upgrading my amp to 6550 tubes,
and in the process possibly hot-rodding the beast for the full 300
watts that 6550 tubes are capable of.
My particular model has a code on the output transformer of 562 180
eia 606 723.
A little investigation of EIA codes (a topic I am familiar with from
other gear) leads me to Schumacher Electric as the manufacturer of the
transformer.
http://www.schumachercorp.com/
I am waiting to hear back from them on the specs of the output
tranny.

I am curious what codes do other folks see on their output
transformers? It's the smaller of the two, should be on the left as
you face the rear of the amp.

[Calaverasgrande]

here are some EIA codes for your edification. Taken from the excellent
http://www.triodeel.com

Manufacturer EIA code

Admiral Corp 101
Aerovox Corp 102
Allen-Bradley 106
American Condensor 109
Amperex (USA) 111
Bendix 125
Centralab 134
Chicago Condensor 135
CTS (Chicago Telephone Supply) 137
Stancor (Chicago-Standard) 138
Cinch 139
Clarostat 140
Coil Engineering 141
Crosley 152
DuMont 158
Eby 160
Eimac (Eitel-McCullough, Inc) 162
Aerovox Hi-Q Division 163
Electronic Tube Corp 169
Ensign Coil 172
Erie 173
Essex 175
John E Fast 178
Freed 183
Gates 187
General Electric 188
General Radio 194
Hallicrafters 199
Hammarlund 201
Hytron (CBS-Hytron) 210
IRC (International Resistance Co) 214
Jackson 216
Jefferson Electric 218
Jensen 220
E F Johnson 222
Kester 224
Lenz 228
Littelfuse 230
Machlett 231
Magnavox 232
Mallory 235
Thordarsen-Meissner 238
Merit Coil & Transformer 239
Micamold 240
James Millen 242
Muter 244
National Co 245
Arvin 248
Ohmite 251
DuKane (Operadio) 252
Packard Bell 254
Philco 260
Philmore 262
Pilot 264
Quam (Quam-Nichols) 270
Radio Condensor Company 273
RCA 274
Radio Craftsmen 275
Raytheon 280
Rola 285
J P Seeburg 289
Mark Simpson (MASCO) 295
Solar 296
Speer 300
Sprague 303
Stackpole 304
Standard Coil 305
Superior Tube Co 310
Sylvania 312
Triplett 321
Tung-Sol 322
United Electronics 323
Utah 328
Wells-Gardner 334
Western Electric 336
Westinghouse 337
Weston 338
Zenith Radio Corp 343
Astatic 345
Essex 352
New York Transformer 366
Altec Lansing-Peerless 391
Foster Transformer 394
General Cement 396
BIC 409
General Transformer 412
United Transformer Corp (UTC) 418
North American Philips (Norelco) 423
Newcomb 437
Gudeman 438
Collins 439
Cannon 440
Good-All 446
Empire Coil 452
Barker & Williamson 461
Oxford 465
Pyramid 472
Radio-Television Products Corp 489
Caledonia 503
Hickok 508
United Condensor 516
Triwec Transformer 524
Ward Leonard 532
Anaconda 547
Midwest Coil & Transformer 549
Standard Winding Co 550
ATR 551
Amphenol 554
Waldom Electronics 555
Electrical Utilities Corp 569
F & V Coil Winding 572
Belden 579
Bogen 589
Shure Brothers 590
Woodward-Schumacher 606 (more of interest to us)
Consolidated 607
Simpson Electric 614
Illinois Capacitor (Condensor) 616
Pickering (Stanton) 631
Central Coil 637
American Radionic 648
Electro-Voice 649
Sangamo 658
Electrical Windings 682
Keystone Hardware 699
Ajax 705
Pioneer 706
Bell Amps 708
Standard Condensor 710
Taylor (aka Cetron-Taylor) 713
Methode 720
Milwaukee Resistor 722
RMC (Radio Materials Corp) 732
Alpha 733
Lewis & Kaufman 738
Russell Speaker Co 748
National Electronics (also Cetron) 749
Grand Transformers 757
Quincy Speaker Mfr Corp 767
Penta Laboratories 771
Muntz 772
Forest Electric 773
Ogden Coil & Transformer 776
Vacuum Tube Products 781
Sonotone 787
McIntosh 793
Harmon-Kardon 794
Varian Associates 809
Dale 816
Triad 830
Better Coil & Transformer 831
Tetrad 842
Klipsch 843
International Rectifier 845
University 847
Drake 851
Precision (Grommes) 871
Acro Products (Acrosound) 878
Litton Industries 879
Mohawk 883
Condensor Manufacturers 885
Connector Corp 888
American Transformer 892
Tresco 897
Coilcraft 906
Aerocoil 908
Acme Coil & Transformer 928
Atlas 932
Magnetic Coil Mfring 933
Oaktron 934
Electrons, Inc 935
Northlake 1005
Pacific 1052