) loud as hell class A circuit so there is little distortion, sounds very punchy and clear very mechanical sounding; SRV and Hendrix heads need not apply.
If you are looking for something original sounding and with a good bit of style, this is it (if you can find one)!
437 volts); this may have gotten higher after 1971, but into the summer of 1971 I'd expect the plate voltages on 6CA7s to be down substantially from the YBA-1A; have the chassis sliding-in ala Fender.Last versions have that easily identified rubber and 'chrome' molding running around each end of the head cabinet; mine is from 1971 and is this last version; 1972 models have no choke; [a 1978 is] black with the black plastic fabric and [has] the baby bumper trim, [it has] two 6CA7 and three 12AX7A tubes in it [and] no fuse holder, just a red reset button I put Mullard EL34s in my YBA-1.I've used it regularily throughout the years, gigging throughout the Detroit area, and later in the E. A plate load of 6K8 would have essentially zero gain and probably lots of other problems.That part of the hand-drawn schematic from 6/1971-1974 is smudged and hard to read, but it's definitely 68K.The YRM-1 is good sounding, but not as responsive, raw, or soulful as my YBA-1. presently using the yba-1 through an old sound city 4x10 which i respeakered with 80 watters. breaks up like a champ when driven and sings sweetly when i turn down the pickup volume(s). It's a beautiful computer-drawn schematic, but an error was made in transcribing the previous schematic.
My personal opinion is that the YBA-1 is better for guitar, while the YBA-1A is preferable for bass. [...] typically playing a new gibson les paul "faded" through them. I got it brand new back in the late 1960s (I traded a dealer my Fender Super reverb even for it). It can be heard on all my recordings, and you can [see] me using it in the videos of my band, Terrain. Specifically, R36 needs to be 68K, not 6K8 as written.
[Oct 2002] US 0 used; one can be bought for under [US] 0 - a total bargain US 0 [used], needed a little work but playable, cheap buy US 9 used, you can get one cheaper CAD 0 [used], good condition, seen at Songbird Music, Ottawa, November 1998 (since January 1999 though, it had changed its condition to 'very good') Rating very good amp My personal opinion is that the YBA-1 is better for guitar, while the YBA-1A is preferable for bass.
My YBA-1A [...] uses 6550s and it's the best rock bass head that I've owned.
typically playing a new gibson les paul "faded" through them. Even after a friend helped me switch the power supply to todays standards and no buzz and shocks occured. I am told it may need some work on the tubes (cost about same as amp itself). 1971 YBA-1A Bass-Master Mark II (top not removable despite later style case), front view, angle 1971 YBA-1A Bass-Master Mark II (top not removable despite later style case), front view 1971 YBA-1A Bass-Master Mark II (top not removable despite later style case), back view YBA-1A Bass-Master Mark II, catalog page YBA-1A Bass-Master Mark II, schematic 1/1969-12/1970 YBA-1A Bass-Master Mark II, schematic 1/1969-12/1970 YBA-1A Bass-Master Mark II, catalog pages, manual, fan conversion, schematic 1/1966, schematic 1/1969-1/1972, schematic 1972-2/1973 YBA-1A Bass-Master Mark II: Looks to be the same as the other one with a choke except it shows 6CA7 as the power tube instead of 7027 (Larry).
(Aaron, Craig, Dan Kukkonen, Dan Lear, Eric Knudsen, Greg, Jay Rogers, John, Jon Aley, Kraig Olmstead, Laws from Lawsstudio Canada, Moon Keith, Tim Baier, viva Analog at bc.ca/~jc, Features volume and tone controls only; it has two inputs, seems to be high and low, no major difference Two 6V6 power tubes This one is a '67 [amp] and is in amazing shape. ) speaker that looks identical to the 15" Jenson in my '64 Fender Vibroverb.
The 2nd one I bought [...] was totally moded for guitar with extra pots on the back and stock EL34s. I [...] have [an YBA-1A Mark II amp] that goes with [the YT-15 cabinet] and it's all sounds great. i believe, though i am not sure, that these 1a's operate in class "a". Other than the old no ground power cord and serious shocks and buzz it sounded better than what i was using.