Vox amp dating
[...] When [the YBA-1] ran on 7027s, it was a rock machine (think Black Crows, Zep, etc.).It probably has a bit less bottom end and more mids and highs now. It must have been one of the last YBA-1 Traynors made.
Sound - Reliability - Price CAD 5 [used], condition unknown, Scarborough, Ontario, Canada, February 7, 2001 Very hard to find. Dyna-Bass, front view, angle (apparently the same as the following) 1963 Dyna-Bass, serial number 0011, front view, angle Features Two channels, deep (bass), and bright (guitar); each has an attenuated and a normal gain input (like the old Marshalls); no reverb Volume control channel one, channel two; treble, bass, low range expander, high range expander (passive); the low range expander may sound like a mid-range, the hi range expander may sound like presence (on Marshalls or Fenders) to some (the section is a virtual clone of that of the Marshall JTM-45); standby switch; pilot light; ground and on/off switch; no fan One main speaker output, impedance is not indicated (runs fine using a cab of eight ohms, also often operated with four ohm loads), one "extension" speaker output also without indicated impedance.I have swapped out the 4M volume pots for 1M, and put a 47K resistor in the NFB loop. Professional repairman required, although schematic is included, weird defects possible. The YBA-1 serial number is 8011108 the YT-15 serial number is 7125596.These mods are worth doing to any Signature/Bass-Master, IMO. CAD 3 used, bad price, amp in average (5/10) condition, Song Bird Music, Ottawa, Canada, summer 1998 US 5 [used], needed a little work but playable, cheap buy US 9.99 [used], seen at September 1998 CAD 9 [used], good condition, seen at Used Music, Ottawa, September 1998 CAD 0 [used], shabby condition, very early (pre October 1966) wrap-around type case model with tube rectifier, seen at Used Music, Ottawa, September 1998 CAD 5 [used], ca.A 1967 YBA-1 is reported to feature a diode rectifier.
The used tubes are, as indicated in the amp: Two 6CA7s (replaceable by EL34s) and three 12AX7As (also called 7025s or ECC83s); plate voltages have always been a question on these units, but I think this may be largely because of confusion with the YBA-1A models that run VERY high plate voltages; most of the YBA-1 models probably come in somewhere +/-450 volts (one has reported 425 volts on plate, another one ca.
Sound It's got the best tone, but it's not the loudest (when used for bass). Both the YBA-1 and YSR-1 each have 4 input jacks, so I can jumper the channels and use both the bright and normal volumes to adjust my tone. 1966 early model, cosmetically it's in pretty good shape, the tolex is perfect, the grill has two tiny snags over at one end, but it seems this amp may have fallen face first at some time, when i got it there were only two of the 'chicken head' knobs, and the front panel screw holes were stripped, so you could just pull it off; there's no dents or anything in the faceplate, not even a scratch, internally it's perfectly clean, no dust or gunk anywhere, recently, [October 1998] CAD 0 used, together with a mathing used 4x12 cab, bought at a pawn shop, October 1998 CAD 0 [used], seen at Used Music, Ottawa, November 1998 [US?