Spectrum I

[guitarandampnz]

After looking for an early Sunn for ages, I finally picked up a late 60's (67, 68?) Spectrum I.  I'd heard Sunn amps before, but never really played through one.  This one just BLEW ME AWAY!  I play clean, bright, and loud, but I've always avoided Fenders because I think they're so boring (everybody plays 'em) and I feel like they tend to sound overly thin.  Being an amp nerd, I've tried tons of other vintage stuff, but so far this one tops 'em all!  Here's a question for anybody with more Sunn experience: I played the amp through a single JBL E130 and it sounded great, but I've got a late 60's Sunn PA cab that looks perfect with the head and will take a crossover and horn in addition to the fifteen.  I've had mixed feelings about other guitar amps I've played with high frequency horns.  Is it worth my time to track down fitting JBL components and set it up semi-stock?

Thanks for any comments!

[TubeMan]

i think your spectrum uses KT88s if im not mistaken..? anyone want to verify this?

anyway.. it may sound really bright sizzly with a crossover and horn.. the KT88 is a relatively hard and clean sounding tube..
alot of people that i know that use KT88/6550s get can get a VERY bright sound through somthing as big as a dual 15 cab with no horn.. so its a judgement call on your part.. but im thinking that it will be really "sizzly" bright with that big ole horn screamin away.

-T

[guitarandampnz]

The amp is definitely stock with EL34's (it's one of the earlier models based on the Dynaco Mk IV 40 watt amp rather than the Mk III 60w, which uses KT88's).  That sizzly horn sound is exactly what I'm trying to avoid.  I'm wondering if I pay the premium $$ for the vintage JBL right-angle horn lens, alnico driver and 1200 Hz crossover that are "stock" (in the 100S for example), plus put a D-130 in it, will I like the sound or will it get that horn sizzle?  I like BRIGHT but not the "broken" sound horns can sometimes impart. I know Sunn's are more popular as bass amps, but has anybody tried a stock "guitar" model with one of the old JBL/horn cabs?  A pox on hi-fi guys stripping them for ebay. . .

[Doommachine]

I think if you go with the horn, you'll end up with too much sizzle. Good for bass but a bit much for guitar, especially with the JBL D130 which are very bright speakers anyway, even making EL34s shimmer...a bit much for me but its all preference. I would suggest swaping the 7025/12ax7 and/or EL34s out for some brighter ones if you just need a little edge.

Just my two cents