Well, what can we say that has not already been said about the Golden Tube Audio SE-40.  This amp was and is a world class performer.  It is unmatched anywhere near its price range!  The SE-40 was definitely the cherry in the GTA lineup.  However, this unit notoriously suffers reliability issues.  If you own a SE-40 which has performed flawlessly, you are a minority.

Enter Sonic Craft. We have re-engineered the SE-40 and SE-40-SE! The following kits were designed to address all the possible needs of your GTA SE-40 or SE-40-SE. WARNING, If you are not an avid soldering hobbyist or require more instruction than those contained in your kit, leave the upgrade to Sonic Craft or your local repair technician! Sonic Craft offers upgrade installation, maintenance, and repairs for your SE-40 or SE-40-SE. Labor is quoted on an individual basis.

NOTE - Before purchasing your kit, you must email us a detailed picture of the bottom side of your amp. This will allow us to email you the proper supplemental instructions for your particular amp. These kits are only applicable to the rev.2 & rev.3, however, those two designations cover 11 different circuit board situations (that we know of).

The SE40REL+ kit contains 42 high-grade components along with a generous supply of Cardas solder, solder wick, solder bulb, and instructions. This upgrade kit encompasses all the “fixes” GTA never had the chance/budget to address. Several resistors in the SE-40 are operating at or near their power limit. Some are experiencing voltage exceeding their max design limit. In many cases, the SE-40 comes with low quality electrolytics. Some caps are exposed to voltages which exceed their rating. Either way, your old electrolytics are quite tired. The factory cathode resistors are a recipe for disaster. One of the rectifiers is a ticking time bomb. Aged power switches are known to introduce noise. Thus, this kit will repair 99% of the SE-40s that are in disrepair. The SE40REL+ will greatly increase the life of your amp and 6SN7/6SL7s. After installation you will be able to use many different tubes (like the SED 6L6GC) while maintaining a sub 640mV bias (remember that this does not cover “all” tubes, but most 6L6GCs, KT66s, etc...). While many of the addressed issues above will improve your sound, there is a part of this kit purely dedicate to improved sound. This is addressed with Mundorf Mcap Supreme Silver/Oils in the interstage coupling and MultiCap RTX multi-section film and foil polystyrenes bypassing the B+ near the OTs. The SE40REL+ is $250.19

NOTE - DO NOT buy the SE40REL+ kit with the intention of upgrading to the SE40SCX at a later date. The SCX would require you to remove many of the parts supplied in the REL+ kit. The parts retained by the SCX kit are under $100. So, if a leveling kit was available, it would probably cost close to $500.

The SE40SCX is primarily focused on sonic improvement . This kit addresses everything covered by the SE40REL+, but is not as budget minded. Sonicap Platinums, large Jupiter HTs, Black Gates, larger PS caps, Mills, Fairchild Stealths, S102s, and a pair of Tung Sol 6SN7s help round out this kit. This 63 component kit includes the same installation accessories as the SE40REL+ along with an adjustment tool. This kit will only be offered for a limited time only (9 kits left as of 4-30-13) due to the scarcity of some components (i.e. Blackgate, Platinums, etc...). When it is gone, it is gone. The SE40SCX is $582.45