Hey guy's! I have just picked up an Egnater Tweaker. I'm pretty impressed so far and at this price ($329 net after coupon and free gift card) I'm gonna Hot Rod the crap out of mine! I feel that this is a great amp for rhythm playing, tons of tone! However, on it's own it doesn't have enough "soul" as I call it, to really dazzle me while playing lead. I'm hoping to be able to Mod it to taste! I've been researching mods and of course, tubes come to mind. I stumbled on this info from Eddie at Eurotubes: Hi Mark, The Egnater Tweaker comes with a pair of 6V6s and when we auditioned these amps at the 2010 NAMM show Bruce was kind enough to answer our questions about bias ands tube swaps. The amp is cathode biased with no adjustment so it will also accommodate EL34s, E34Ls, KT77s and 6L6GCs. The JJ 6V6's are a very full and round sounding tube and when pushed at higher volumes are a little crunchier in the mid and upper mids than a 6L6 is. The standard JJ EL34 is just like the old European EL34's. These are a bit soft with a shallower low end and a smooth breakup with a nice crunch, a typical high quality EL34. Standard EL34 tubes are not real tight and are known for a slightly looser and more vintage feel. The JJ E34L's provide a deeper low end and are more aggressive and punchy than an EL34. The E34L is tighter with slightly more headroom and power with a more aggressive crunch, a very articulate British tone. The JJ KT77's have even a bit more low end extension than the JJ E34L's and they have a nice sizzle in the top end that is not brittle. The clean tone is very fat and full and the crunch at loud volumes has more of a chunk to it and it's very punchy but not quite as aggressive as the E34L, a great tube for rhythm and solo work if you like the pushed mid and upper mid tone that all EL34 type tubes have. So for a comparison the JJ 6L6GC's have a little more low end than the KT77's, but are a cleaner tube with a later breakup and they are not as mid range heavy, more of a traditional Fender type tone. They will also give the fattest and most linear full spectrum sound of all the small bottle octal tubes which also makes them a great tube for just about anything from Rock to Jazz to Country. For the front end we typically use with three of the ECC83S preamp tubes with one being balanced for the phase inverter in V3 which is the preamp tube closest to the power tubes. This will eliminate any dead spots due to phase cancellation. Another option would be if you want any of the preamp tubes premium graded for gain. The high gain ECC83S's have about 10% more gain than standards which adds a bit of bite and a sharper dynamic but does not hurt the clean tone. The other attribute that these tubes have is a faster filament rise time which is great for an EVH, Malmsteen, Petrucci or Satriani type style and is also good for fast palm mute styles. If you decide to use these I would use them in V1-V2 with a high gain balanced ECCC83S in V3 which would add 12.75 to the cost below. Using the Gold Pin JJ tubes would also be an option if you want the best of the best. The main difference with them is that they are smoother in the top end and a little richer in the mids. They also have a touch more presence in the highs. They are however expensive, the ECC83S standard Gold Pin tubes run 19.75 and the balanced ECC83S Gold Pin tubes run 22.00 so it would add 29.25 to the cost below. A full retube with a matched pair of the JJ 6V6s along with three ECC83S's (one balanced for the Phase inverter) would run 60.25 and we can ship them for 8.50 by Priority mail with a 3 day delivery anywhere in the US. Youre welcome to stop by and pickup tubes as well. Give us a call for directions. If you decide to place an order you can do so online here: https://ssl.eurotubes.com/cart/ This is a certified secure system, but please don't feel obligated to order online you are always welcome to just give us a call at 503-659-7401 during business hours which are from 9AM to 5:30PM west coast time to place an order personally. You can also place an order by FAX at 503-659-7385. All that's necessary is your shipping address and a VISA, MC, Discover or American Express number including the expiration date. If you decide to order by phone, feel free to give us a call during business hours as well! Thanks, Eddie Just thought I would pass this along!