Please let me know if you think I've made the right trade-offs to nail this!
A number of claims attract me to this:
ayan wrote: ...the earlier 80s circuit (very easy to play, good crunch with OD, and screaming leads with OD + PAB)
heisthl wrote: If I could have only one it would be non-HRM. There is no substitute for the high you get when every note can sustain forever - it really is the "talent in a box" sound and if you play like I do you need all the help you can get....
Some good threads to check out:ayan wrote: I have one amp set up that way, Skyliner with mid switch, and one with the early 80s circuit with a deep switch instead. The Skyliner sounds great with a Tele (better than the 80s), and it sounds great with my 335 on the bridge pickup (the 80s sounds just as good). But, t does not like the Strat very much at all. On the other hand, the 80s sounds best with the Strat and can be used with the 335 on the neck pickup.
{snip}
Gil
http://ampgarage.com/forum/viewtopic.php?t=3615 Discussion on non-HRM variations, pros and cons.
http://ampgarage.com/forum/viewtopic.php?t=3839 Gil's summary of his recent 100k/1.5k build... with lots of discussion on the early 80s high plate versions too.
Some quotes that guided the value selection:
ayan wrote: I have seen more than one high plate amp, non HRM, but they have been 220K/150K for both V1 and V2, have had a 1uF bypass cap on V2 and a .047 CL2 coupling cap. An earlier version was the same, but with a .022 CL2 coupling cap.
Cheers,
Gil
ayan wrote: I have seen some higher plate amps (non HRM) with .05uF coupling cap on CL2 -- all but one actually. They did have the smaller, 1uF cathode bypass cap on CL2. However, that stuff will make some difference in the low end, but not too much in the "texture" of the overdrive, IMHO. The size of the resistors imparts a much stronger character that cannot be dialed out with coupling or cathode bypass caps.
Gil
ayan wrote:Perhaps we should consider making that late 80s. The early 80s all had the classic EQ with the Deep switch, etc. The earliest Skyliner conversion I have heard of dates from 1986; the earliest chassis reflecting the MID switch that I know of dates from 1987.dogears wrote:Actually, a few corrections.
{snip}
Lastly, there as many as dozens of non HRM Dumbles with the Skyline stack. Even the infamous Ultrasound tan one. It was his standard in the 80s....
Cheers,
Gil
ayan wrote: What I call the early 80s amp is similar to the Skyliner, but with a few important differences. Schematic is not out because there are not that many of those amps around that have not been "upgraded" to either Skyliner of HRM, and because the earlier schematics have been kept underground at the orginators' request. But, I can comment on the differences between that and say something along the lines of #124:
1. 220K/150K plate and 3.3K/2.2K cathode resistors for both V1 and V2.
2. V1A grid stopper is 22K, as opposed to 33K for the 100K amp.
3. Tone stack has a .047uF midrange cap.
4. Bass and middle tone pots are 250KA (no .001uF cap across it) and 100KL, respectively, and the tail on the bass pot is 1K, not 10K.
5. Deep Switch instead of Mid switch. The Deep switch, if you have not tried it, is very nice: it adds a bit of bass to the sound, tames the highs slightly and, best part, is that it also tames down the PAB mode. In contrast, I have found the Mid switch to have a lot of limitations.
Gil
dogears wrote: Although 124 is a nice sounding amp, I would not use its values as gospel. We have several other degooped "grail" specimens to consider. They all have 100K drive pots and 100K pre OD trimmers w/220K feeding them. Several have fairly large bright caps on the master!
All in all, I prefer 100K drive pot and a 100K OD trimmer. YMMV.
ayan wrote: 4. I have it on pretty good authority that back in 1982, RF's amp looked just like I just described.
Gil