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Post by jvdunne on Dec 1, 2006 8:56:36 GMT -7
I would appreciate hearing from one and all on this. I have a CG head, with the Doc's 2x10" cab. I would like to get a bit more clean headroom for playing out. Would changing the stock tubes do this? Any specific rec's? Where would I buy these tubes? Thanks.
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Post by bustertheboy on Dec 2, 2006 2:48:03 GMT -7
welcome jvdunne- the usual answer is to put a 12BH7 in V2- the phase inverter for more headroom. It works as it lowers the gain. The amp appears to run cleaner though you have to set the volume control higher to get the same volume of course Brett ps try www.tubedepot.com or www.kcanostubes.com for nos tubes or anos (almost new old stock- these test as new after use in non destructive situations)
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Post by Don on Dec 2, 2006 11:43:27 GMT -7
Myles is the man to speak to. You'll find him here on the forum.
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Post by Don on Dec 2, 2006 11:48:26 GMT -7
I would appreciate hearing from one and all on this. I have a CG head, with the Doc's 2x10" cab. I would like to get a bit more clean headroom for playing out. Would changing the stock tubes do this? Any specific rec's? Where would I buy these tubes? Thanks. Also, go to the Tubes Forum here. There's a lot of good information from some very knowledgeable people.
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Post by mojowrkn on Dec 4, 2006 12:31:08 GMT -7
Hey jvdunne,
I am no "expert", but I do run my Ghia head this way. Use a 12Bh7 in v2 as mentioned before, and slide the 5751 over into v1. Also, you can order EL-84's that are bias colder that will give you more headroom.
I do all three of these things, sometimes going with a 12ax7 in v1, and it sets the sweet spot for the Ghia in exactly the right spot for the volume I play at. (Smallish clubs) Hope that helps.
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Post by canes on Dec 4, 2006 20:49:49 GMT -7
I also have a ghia 2x10, but a combo. I also wanted more clean head room so I ordered a matched 12bh7, it turned out to be microphonic so i kept using a 5751 matched, and normally have plenty of headroom in live situations. With a decent sound man I even have plenty at open-mic blues jams with 2-3 guitar players. For what its worth i think the NOS GE 5751 sounds best in V2. Jason
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Post by bustertheboy on Dec 5, 2006 1:49:03 GMT -7
I also have a ghia 2x10, but a combo. I also wanted more clean head room so I ordered a matched 12bh7, it turned out to be microphonic so i kept using a 5751 matched, and normally have plenty of headroom in live situations. With a decent sound man I even have plenty at open-mic blues jams with 2-3 guitar players. For what its worth i think the NOS GE 5751 sounds best in V2. Jason i'd second that- great definition oand drive. I love a nos 12ax7 in v1
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Post by jvdunne on Dec 5, 2006 6:51:46 GMT -7
JVDunne here . I am displaying my ignorance here, but 1) What does V1 and V2 refer to? I guess ite the pre-amp tubes, but are the spaces where they go marked as such? 2) Cold biased EL-84's- is that what I ask for, and are some better then others? 3) Is a 5751 the same as a 12BH7? Thanks for your patience.
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Post by canes on Dec 5, 2006 10:39:22 GMT -7
V1/2 refer to the tube positions. V1 is the tube furthest from the output (larger) tubes, at least in my amp. In a ghia V1 is typically stocked with a 12ax7 or ECC83 type tube, V2 (the phase inverter) with a 5751, although thats interchangeable with 12ax7's (which provide quicker breakup/less headroom) and 12bh7's (which provide more headroom). As far as El-84s go, the Doc recommends #6 hardness (GrooveTube rating) for the Ghia, thats what came in mine and they sound good. I think the higher the rating the more headroom, but I dont believe they'll sound as good/warm. Somebody chime in if i've made any mistakes. Jason
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Post by myles on Dec 6, 2006 11:48:49 GMT -7
Try a 12BH7 in V2 (v1 is most close to the input jack and v2 is closer to the output tubes).
More clean headroom and a cool jazzy tone as well.
Canes above is corrrect, the high the rating number the more clean headroom but this is more grid biased amp related than cathode biased amp related. I like 6's in my own amps and will use a 7 at times but I stay in the 4-7 range all the time with any cathode biased EL84 amp.
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