Members perfect5th Posted January 23, 2017 Members Share Posted January 23, 2017 Hi folks,I've had a Deluxe reverb RI for 7-8 years. Just started making a nasty snap periodically. No rhyme or reason. I don't know all the tube stuff you guys talk about. I'll take it to a pro but wanted to check if there was something simple I should look at.nelson Link to comment Share on other sites More sharing options...
Moderators daddymack Posted January 23, 2017 Moderators Share Posted January 23, 2017 could you give us more to go on? When does this 'snap' happen? How loud is it? Link to comment Share on other sites More sharing options...
Members perfect5th Posted January 23, 2017 Author Members Share Posted January 23, 2017 could you give us more to go on? When does this 'snap' happen? How loud is it? louder than the music I'm playing. I can't assign it to any occurrence I'm doing. Guitar (Ibanez, Benson) and cord is all good. A gentle push in on all tubes affirms all seated. Nasty snap it is. Spoils the mood Link to comment Share on other sites More sharing options...
Members WRGKMC Posted January 25, 2017 Members Share Posted January 25, 2017 First I'd ask if it happens with the cord removed. If it does, it may be one of the preamp tubes. If you hear the pop then a reverberation afterword's then its either a channel preamp tube or a reverb driver tube.These are 12AX7 tubes which tend to go microphonic within a year or two in combos because the speaker vibrations rattle them to death. The popping comes from elements so beat up they begin to arc out. My opinion is, when you have one tube going bad, the others aren't far behind. You should buy a new set including a new set of power tubes.They are not hard to change on that amp and you can save yourself $150 for having a tech do it and also say yourself another hundred or more on the cost of tubes. If you don't want to touch it at least buy the tubes yourself and have them put in.I recently changed the tubes in my Fender Blackface. I tried out 4 different brands before settling with Electro Harmonix/The difference between them and the Groove tubes I had in there was like night and day. It was like taking a blanket off the speaker for tone.. The 12AX7 tubes can simply be plugged in. There is no bias for them. There is likely one 12AT7 as an inverter which needs no biasing either. You can google up how the power tubes are biased of have them done. Link to comment Share on other sites More sharing options...
Members perfect5th Posted January 26, 2017 Author Members Share Posted January 26, 2017 Thanks for the reply. I'll take your advice and replace them all. Must admit, I've always played ostrich when you guys start talking bias and such. I just googled it and have the basic understanding. Appears the path of least resistance would be to go with stock tubes.I'm pleased with the sound I get from the amp.My next question,where does one buy tubes? There are two 12AT7, four 12AX7A all in metal sheaths. Then glass 5AR4 and 6V6GT. nelson Link to comment Share on other sites More sharing options...
Members onelife Posted January 26, 2017 Members Share Posted January 26, 2017 Tubes are available at guitar shops and music stores and can be purchased online. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted January 26, 2017 Members Share Posted January 26, 2017 The three on line sites that have the best prices are... http://www.thetubestore.com/Resources/Product-Reviews/12AX7-Tube-Reviews https://www.tubedepot.com/t/tubes/preamp-tubes/12ax7-ecc83-7025-cv4004 https://www.tubesandmore.com/ I've ordered from all of them but prefer Tube Depot. These places do give you tube comparison charts which are spot on. They will give you an idea to the quality and tones the tubes give you.Its similar to buying strings which can give you different tone and action. Also be sure you buy matched pairs when buying power tubes. https://www.amplifiedparts.com/tech-corner/12ax7-comparison-current-made-tubes https://www.tubedepot.com/tube-comparison-tool http://www.thetubestore.com/Resources/Product-Reviews/6V6-Tube-Review I'd also suggest - your amp undoubtable has a 12AT7 inverter tube. I did a check on all the ones out there and these by far have the best specs with the lowest noise out of any I've found. These are new old stock US made Joint Army Navy military tubes so they're quality is a step above most commercial tubes. https://www.tubedepot.com/products/12at7wc-jan-philips Link to comment Share on other sites More sharing options...
Members perfect5th Posted February 7, 2017 Author Members Share Posted February 7, 2017 The three on line sites that have the best prices are... http://www.thetubestore.com/Resources/Product-Reviews/12AX7-Tube-Reviews https://www.tubedepot.com/t/tubes/preamp-tubes/12ax7-ecc83-7025-cv4004 https://www.tubesandmore.com/ I've ordered from all of them but prefer Tube Depot. These places do give you tube comparison charts which are spot on. They will give you an idea to the quality and tones the tubes give you. Its similar to buying strings which can give you different tone and action. Also be sure you buy matched pairs when buying power tubes. https://www.amplifiedparts.com/tech-corner/12ax7-comparison-current-made-tubes https://www.tubedepot.com/tube-comparison-tool http://www.thetubestore.com/Resources/Product-Reviews/6V6-Tube-Review I'd also suggest - your amp undoubtable has a 12AT7 inverter tube. I did a check on all the ones out there and these by far have the best specs with the lowest noise out of any I've found. These are new old stock US made Joint Army Navy military tubes so they're quality is a step above most commercial tubes. https://www.tubedepot.com/products/12at7wc-jan-philips This is great. Thanks for the writeup and sources. I've got everything book marked. Having never done this it is surprising the $$ involved. No matter, can't take it with ya. Want to do it right. Thanks Link to comment Share on other sites More sharing options...
Members WRGKMC Posted February 8, 2017 Members Share Posted February 8, 2017 I've bought allot of 12AX7 tubes over the years. I have at least a dozen different types in different pieces of gear now. I'm also old enough to have used all the vintage tube types in the past. I used to like running the old RCA tubes in my Fender amps. They gave me a beefier tone. In my amp repair days I used to repair allot of foreign gear too. Amps from Holland, Germany, Sweden, England etc. All of them would have European tube versions so I was able to hear how they sounded too. You eventually come to the conclusion, old tubes sound bad no matter who makes them and new tubes often have small but significant tonal differences. You may not hear the differences clearly from a guitar amp because guitar speakers have a limited frequency response and roll off most of the high frequencies where the various tube differences are heard. On my last experiment, I compared all my spare 12AX7 tubes using a microphone preamp instead of a guitar amp, Reason being a mic preamp is full frequency and you're able to hear the high and low frequency differences between the tubes much better. I went through the 3 different Sovtec tubes, several Chinese, Groove tube, JJ, Telefunken, Mesa, Electro Harmonix, Fender, Marshall, Tung Sol, Ruby, An old Westinghouse, RCA, and Sylvania. There may have been a few more. The two that stood out above the rest were the Westinghouse and the Electro Harmonix. The Westinghouse was old and microphonic so It wasn't a good option, plus new ones are impossible to find now. The RCA and Sylvania were beat too. I settled with using the EH and have been very happy with them. They key is this. Many of the tubes were originally designed for Hi Fi use. Your better Hi Fi systems had enhanced EQ circuits and Speaker cabs that contained a crossover that separated the frequencies for the woofer and tweeter. If the manufacturer selected one brand of tube and its high or low end was a little weak they simply made up the difference balancing the circuit or the speaker cab to get a fuller fidelity. With guitar amps, the heads produce mostly midrange tones and the EQ controls are designed to attenuate in those ranges. With the EQ's full up you hear the full frequency of the amp which isn't always complementary. The tone controls remove frequencies and carve out a response suitable to most instruments. The full frequency drives the speaker but much of that is rolled off by the speaker itself. If that speaker rolls off at say 5Khz you wouldn't think a tube that has a strong 12Khz drive would be any different then one that has a strong 9Khz because the speaker wont produce those frequencies. This is the hook. It may not make a difference if you play 100% clean with zero saturation. When you push the amp harder that's where the difference in the tubes can reveals itself. Its how and how much the tubes produce harmonics when that are pushed into saturation.A tube with a stronger high end will saturate the speaker better at its upper limits. A tube with a weaker high end and stronger bass may saturate better at lower frequencies. I really cant tell you wants best - only what I prefer for my own playing style using the amps I own and prefer. The tubes I prefer may not be the best for your particular amp and playing style. Its simply going to be something you'll have to try and then decide if its better or not. Its not easy to make those comparisons either. If you use a set of tubes for a couple of years they fatigue and you don't even notice it. New tubes of the same kind are going to sound better just like new guitar strings do. For me the EH were better then all others for my Fender amp but I prefer a nice rock tone and some sparkle when I run it clean. Others can sound more mellow and break up at lower volumes, Link to comment Share on other sites More sharing options...
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