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bubbaike

Tubes??

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Since I may need to replace tubes in my Blues Custom 30 one day, what would you guys recommend and why? I really like this amp except the weight. Had it only 3 days got it in a trade. Thanks for any help and info about this amp. By the way I'm from Arkansas. Guitars: 2000 Fender MIM Strat with 57/62 pickups; 2007 Highway 1 Srat with Seymour Duncan SSL 1 pickups; Canvas CST50 semi-hollowbody. Amps: Fender Stage 160 and Epiphone Blues Custom 30.

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Hi, I've spent months modding/unmodding the circuit of this amp and can honestly say the stock circuit is fine, just needed better CHOICE of valves, not just better valves. You will find that when you install some valves the amp looses bass and gains a chimey yet ice-pick tone. This is what many people have tried to compensate for by modding. The mods do balance the tone but ruin the distortion characteristics of the amp. I eventually settled on this combination.

 

V1 NOS General Electric 12AX7WA

V2 Cryo JJ/Tesla ECC83s (BTW cryo treatment is probably bol*ocks)

V3 NOS Mullard ECC81/12AT7/CV4024 (reverb driver position)

V4 NOS Mullard ECC81/12AT7/CV4024 (phase splitter)

V5 Electro Harmonix 12AX7EH (original stock valve)

V6 and V7 Cryo Harma 6L6GC

V8 Cryo Harma GZ34/5AR4

Plate resistors on the phase splitter are now carbon comp, should give nice 2nd order harmonics when playing loud on stage. (BTW there's no noticeable noise floor increase)

Snap back handles on each side of the amp, I've bought em, just need to bolt em on!

 

The difference is AMAZING!!!

 

As stock all ECC83's were Electro Harmonix 12AX7EH's , the 5881's were Sovtek 6L6WGC's and the rectifier was a Sovtek 5AR4. Still sounded bludy good! FAR better than most amps I've heard at the music venue where I've worked for 8 years. Just lacked a bit of bass end thump and top end shimmer for me to be really happy, so I started experimenting. Over a period of months I gathered a selection of preamp valves and a new set of 6L6's. I've tried a million combinations of valves and circuit mods, eventually I found the one listed above and bought a solder sucker and cleaned up the circuit board, It's now better soldered than when it was new!

 

The Harma 6L6GC's instantly gave the powerful bottom end and clearer top end I was looking for. Magic.

 

For my Fender Strat the clean channel now only breaks up when the volume is almost on full, my Gibson SG breaks up sooner and it's a classy grit thats very usable. I think that happened when I installed the GE in V1. The overdrive channel has a thicker more refined saturation that really lets the tone of the guitar shine through, a lot like big fender amps do. None of that flat fizzy distortion that it used to have (it used to sound more marshally, now its more fender/vox). The Mullard 12AT7 as the phase splitter has given a warm 3D depth to the amp that i really love, especially when cranked up! Great for the bluesy/rocky tone I've always aimed for! I'm sure the JJ/Tesla in V2 helps the distortion sound big and powerful while the Mullard PI warms it up.

 

The 12AT7 makes the reverb a little better, less overbearing.

 

Not sure about the rectifier, I havent had chance to A/B on stage like i did when I lived above the venue where i work.

 

I'm also modding the EQ/tone stack to be more fender like; I'm going for the Deluxe model stack. Dont have the new caps yet though but I'll post some before and after samples when its done.

 

 

Sorry this post is all over the place! Too much info and no time to organise it, I'm going to work now...

 

Later,

Andy

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I have replaced the Sovtek 6L6 tubes with Harma 6L6GC STR. A definate improvement.

 

As for the preamp it's mix and match. In v1 I fitted a Sovtek 12AX7LPS and in v5 I have a Mullard 12AT7 to calm down the reverb.

 

I have snipped C3,C5 and C6 like others have done but I'm about to wire them back in via a mini toggle switch which will act as a bright switch. I'm still considering fitting a presence control. I have just taken delivery of a pair of EH EL34's which I'm gonna fit after some alterations. I'll let you know how that one goes. One thing I will say is this. Watch out for that schematic that Epiphone has issued, quite alot of component values are different on my amp to what the schematic says.

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