CEB Posted September 29, 2013 Share Posted September 29, 2013 I bought a new amp on impulse. I used it last night at a gig. It was sort of mediocre but it is the right size for my needs. It is a VHT Lead 20. It has the stock cheap Chinese tubes. My questions are if I put good tubes in it could there be a noticeable improvement in tone. 4- 12ax7. 2- EL84 What if any tubes would you replace. My other question is on my Boogies I would just swap out tubes myself. On my old Fenders I would have my amp guy do it and adjust the bias. The VHT manual does not say squat. Would this amp need biased if I switch tubes or is it like my Mesa. "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
CEB Posted September 29, 2013 Author Share Posted September 29, 2013 According to a brother at the Tele forum this is a fixed bias amp and should have the bias adjusted. Bummer. Mesa amps are plug and play. I like that. Who makes a good matched pair of new EL84s. This is only a $350 amp. I think it may have potential as a working amp if good tubes help a little. Thanks "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted September 29, 2013 Share Posted September 29, 2013 EDITED re: the driver/"phase-inverter" tube A fresh compliment of tubes, all selected to cater to your wants and needs, will improve the tone of your amp. Be sure to include a new good, strong Driver/"Phase Inverter" tube that tests good for driver-duty on V3A (the first of its two internal triodes); it's important to have replace the driver along with the matched output-tubes. (Though commonly referred to as a "Phase Inverter" in this position, in this particular amp design, only one side of the tube's two internal triodes is used to drive the output-tubes.) I can HIGHLY recommend Ruby EL84CZ's, which are the same actual tubes as the GT-branded GTEL84S's that I got from Groove Tubes when Myles Rose was still there; mine have lasted waaay longer than expected. Get a matched quartet and you've got identical sets of matched output-tubes for spares/r eplacements. (These are also the same as some JJ EL84', but easier to find in matched pairs and quartets.) Don't even waste your money or time on NOS EL84's- other types of tubes, like EL34's, 6L6's, yeah, but not EL84's. These Ruby EL84CZ's will do ya VERY WELL for less and ANY NOS EL84 is likely to last too short a time to make it worth the price. Talk to Doug at Doug's Tubes; discuss what you want from your VHT Lead 20, what you already like, what you'd like more of and less of, point out requiring a driver-tube that uses only V3A to drive the output-tubes... he'll steer you right with socket-specific tube selections for preamp-tubes and the driver/phase-inverter tube. And the results will be repeatable in the future when you eventually need to replace tubes. Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
Larryz Posted September 29, 2013 Share Posted September 29, 2013 If you like the amp and it does the job for you, when and if you decide to re-tube: buy good quality tubes even if they cost more than the amp is worth. And, don't forget to ask Myles... Take care, Larryz Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted September 29, 2013 Share Posted September 29, 2013 If you like the amp and it does the job for you, when and if you decide to re-tube: buy good quality tubes even if they cost more than the amp is worth. And, don't forget to ask Myles... Yhup; ultimately, a car is only as good as its tires. Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
CEB Posted September 29, 2013 Author Share Posted September 29, 2013 Thanks a lot. I want good cleans. I don't want early breakup. The thing that seem funny was I dimed the treble control and I was playing a Tele. The VHT looks like a Vox type amp. I would have expected to have had to cut the Treble. It was an outdoors show though. A 20 watt 1 12 combo was fills an immediate need. My 50 watt Boogie is too much and my 5 watt Blackstar is not quite enough. Thanks again. "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted September 29, 2013 Share Posted September 29, 2013 Thanks a lot. I want good cleans. I don't want early breakup. The thing that seem funny was I dimed the treble control and I was playing a Tele. The VHT looks like a Vox type amp. I would have expected to have had to cut the Treble. It was an outdoors show though. A 20 watt 1 12 combo was fills an immediate need. My 50 watt Boogie is too much and my 5 watt Blackstar is not quite enough. Thanks again. You could try a 5751 like one of these or some of these for V1 (the first preamp tube, closest to the input), instead of a 12AX7, for cleaner, lower gain. Less gain than a 12AX7/7025/ECC83, more than a 12AY7, good tone, much better than a 12AT7. SRV used to put these in the 1st socket of some of his amps. Be sure to replace the driver/"phase-inverter" tube along with the output-tubes, they work and wear-out together as a team, and use a good, strong, "balanced" one with matched triodes. This can make a HUGE difference in overall quality of sound and feel! Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted September 29, 2013 Share Posted September 29, 2013 Please note- I have gone back and edited my previous post regarding the Driver/"Phase-Inverter" tube. In this amp's circuit design, a "Matched"/"Balanced" Phase-Inverter is of no benefit, as only one side of the tube, one of its two internal triodes, is used to drive the output-tubes. So, a tube that tests good for Driver-duty on its "A" triode would be beneficial, but a "Matched"/"Balanced" tube would be wasted. Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
CEB Posted September 30, 2013 Author Share Posted September 30, 2013 Thanks "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Bartholomew Posted September 30, 2013 Share Posted September 30, 2013 Cheap Chinese tubes produce lower volume than JJ and are not musical. Been there, done that. Amps ship that way to keep the cost down at a retail level rather than adding $100 or whatever for good tubes...keep them as spares. Been round the block but am not over the hill... http://www.bandmix.ca/jamrocker/ Link to comment Share on other sites More sharing options...
Lokair Posted September 30, 2013 Share Posted September 30, 2013 well if you need a match set of the el84 s , I like the mesa el84 sold in pairs for like 30$ or less . I use em but I buy a pair then split them for two low wattage amps, but they do indeed sound good. Lok 1997 PRS CE24, 1981 Greco MSV 850, 1991 Greco V 900, 2 2006 Dean Inferno Flying Vs, 1987 Gibson Flying V, 2000s Jackson Dinky/Soloist, 1992 Gibson Les Paul Studio, Link to comment Share on other sites More sharing options...
CEB Posted October 5, 2013 Author Share Posted October 5, 2013 2 weeks ago the amp did not sound so great but last night it kicked ass. Has to turn the master down twice. Hotter the amp got the louder it seemed to get but better it sounded. It was essentially a new amp when I got it. Maybe there is some sort of break in period. Last week was an outdoor event and we only did about an hour due to rain. Last night was a full 4 hour deal. I liked the tight low end. I haven't done anything to the amp yet. I bought it because it was $350 stop gap until I could afford what I really want but right now I am liking this amp. VHT has not sent me a tube location chart yet. Maybe I will change all the ax7s. "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Lokair Posted October 5, 2013 Share Posted October 5, 2013 Yea tubes amps sometimes need to get up to temp. My pro-valve power amp likes heat, so I turn it on first while setting up, Then I turn on my mesa pre and it only likes a bit of heat so I use a fan across it. Too much time with out a fan makes the pre sound sloppy. This is why they will soon be in separate small racks. Also try burning in your tubes leave the amp on for like an hour and then try it, and come back another hour and try it. You may have an amp that just gets better with heat. I have tube roller friend who turns on his amps with new tubes for like 24 hours with a tone generator and swears by breaking in his tubes this way. Lok 1997 PRS CE24, 1981 Greco MSV 850, 1991 Greco V 900, 2 2006 Dean Inferno Flying Vs, 1987 Gibson Flying V, 2000s Jackson Dinky/Soloist, 1992 Gibson Les Paul Studio, Link to comment Share on other sites More sharing options...
Larryz Posted October 5, 2013 Share Posted October 5, 2013 The speaker may also be breaking in and making things sound better... Take care, Larryz Link to comment Share on other sites More sharing options...
CEB Posted October 5, 2013 Author Share Posted October 5, 2013 That is true. I was not thinking about the speaker. The speaker is a Celestion. Not sure which model. It has a gold colored label. "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
CEB Posted October 10, 2013 Author Share Posted October 10, 2013 This VHT has about 6 hours of operations under it's belt. The thing sounds better the more I use it. I think it is the G12H30 Celestion breaking in. VHT sent me schematic today. I am waiting on a tube location chart. The lead tech is at a trade show so there is a delay. I'm thinking of putting new Ruby or JJ EL84s in the amp. My amp guru back home has both including matched Boogie EL-84s which are made by JJ. I'm in Nashville until Saturday. I bought the thing because it was cheap but I am starting to like this damn thing. I am going to spend more to have a case cut for this amp than I spent on the amp. That sounds kind of stupid. I was never accused of being a genius (excluding sarcasm ) "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Larryz Posted October 10, 2013 Share Posted October 10, 2013 In another thread I remembered DBM talking about how much better his new amp sounded as his new speaker was breaking-in... Take care, Larryz Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted October 10, 2013 Share Posted October 10, 2013 This VHT has about 6 hours of operations under it's belt. The thing sounds better the more I use it. I think it is the G12H30 Celestion breaking in. VHT sent me schematic today. I am waiting on a tube location chart. The lead tech is at a trade show so there is a delay. I'm thinking of putting new Ruby or JJ EL84s in the amp. My amp guru back home has both including matched Boogie EL-84s which are made by JJ. Go with Ruby EL84CZ's, which are the same actual tubes as the GT-branded GTEL84S's that I got from Groove Tubes when Myles Rose was still there; mine have lasted waaay longer than expected. Get a matched quartet and you've got identical sets of matched output-tubes for spares/replacements. (These are also the same as some JJ EL84', but easier to find in matched pairs and quartets.) They'll make a new amp out of it. A Sovtek 12AX7LPS that has been tested to show at least 1.0mA of plate current would make an excellent, reasonably priced driver-tube. That's what I'm getting for my Fuchs, to go with a sweet NOS Tesla EL34. I bought the thing because it was cheap but I am starting to like this damn thing. I am going to spend more to have a case cut for this amp than I spent on the amp. That sounds kind of stupid. I was never accused of being a genius (excluding sarcasm ) Don't feel alone! I will have spent more on tubes and a replacement speaker for my Carvin Vintage 33 than I paid for the amp! Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
pinkjimiphoton Posted October 14, 2013 Share Posted October 14, 2013 you'll never get good clean tones at stage levels with anything with el84's in it. according to this page: http://www.tdpri.com/forum/archive/index.php/t-272691.html it's a fixed bias amp, so yes, you can change tubes with impunity. in this kind of amp, the bias is generally set with a cathode resistor... yes, it's fixed, but it makes the tubes self bias. i would agree with caev's assessment on the tubes. nice little amp, but not really designed for clean tones. if you need clean tones out of a little amp like this, i'd reccomend a good fuzz. then, with the guitar rolled way down, you'll be able to get a cleaner tone than with the fuzz off. http://www.sweetrelief.org/ https://www.wepay.com/donations/memorial-stone-for-juliane-pocius Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted October 14, 2013 Share Posted October 14, 2013 you'll never get good clean tones at stage levels with anything with el84's in it. it's a fixed bias amp, so yes, you can change tubes with impunity. in this kind of amp, the bias is generally set with a cathode resistor... yes, it's fixed, but it makes the tubes self bias. nice little amp, but not really designed for clean tones. FWIW, I really like the way my 4xEL84 Carvin Vintage 33 cleans-up when I roll-back my guitar's volume-knobs, with the "Soak" (pre-gain) set around 9:00 to 10:00 O'Clock (NOT the dial-numbers) and the (master) Volume set to about 11:00 O'Clock or Noon or so. It's a different sort of clean- very thick, fat, woody, full and throaty, not the typical Fender type of clean which, by comparison, has the middle scooped some and the treble cranked. It has a sort of a "Jazz" clean sound that way, but with some more upper-mids, treble, and presence. (And furthermore FWIW, on this particular amp, odd as it may seem, I set the "Soak" (lead/overdrive/distortion/dirt) Channel's Bass MAXED, Middle 11:00 O'Clock, Treble MAXED.) if you need clean tones out of a little amp like this, i'd reccomend a good fuzz. then, with the guitar rolled way down, you'll be able to get a cleaner tone than with the fuzz off. Good call! That can work, depending, of course, on the fuzz pedal being used. Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
Larryz Posted October 15, 2013 Share Posted October 15, 2013 I like the typical Fender clean sound with no pedals...lower powered amps can get lost in the mix easily when trying to play clean, if the group is not sensitive. Take care, Larryz Link to comment Share on other sites More sharing options...
CEB Posted October 23, 2013 Author Share Posted October 23, 2013 I am peeved with VHT. I have asked 5 times for a tune location chart. I just want to know which one is the Phase inverter. I assume it is V4. V4 is the one closest to the EL84s. But I don't think this is always the case. "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Bartholomew Posted October 24, 2013 Share Posted October 24, 2013 You can pull the tubes and read the numbers which would indicate what you want to know. Easier to get it in an e-mail but if it isn't happening... Been round the block but am not over the hill... http://www.bandmix.ca/jamrocker/ Link to comment Share on other sites More sharing options...
CEB Posted October 24, 2013 Author Share Posted October 24, 2013 I'm spoiled. If there is ever any question regarding anything Boogie I can call Mike Bendinelli directly and he answers anything I want to know. "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Caevan O’Shite Posted October 24, 2013 Share Posted October 24, 2013 I know it's a PITA, but if you carefully remove the chassis (being careful not to break any tubes, or do any other damage!), seeing where a given tubes wiring and/or PCB-traces lead to will usually give you a good idea. The driver/phase-inverter tube is almost always the "preamp tube" (12AX7, 12AT7, 12AU7, or other "little" tube) that's located closest to the output-tubes. In fact, I'd be surprised if you can give me an example where that isn't the case. Ask yourself- What Would Ren and Stimpy Do? ~ Caevan James-Michael Miller-O'Shite ~ _ ___ _ Leprechaun, Esquire _ ___ _ Link to comment Share on other sites More sharing options...
Dr. Ellwood Posted October 24, 2013 Share Posted October 24, 2013 TUBE FUNCTION AND LOCATION CHART PITTBULL FORTY - FIVE 1X12 COMBO Each 12AX7 has two sections/functions. Section A is shown first, Section B is second. Factory recommended tubes are listed under each location. Numbering sequence is right to left looking at back of amp starting with the row closest to front panel of amp. V1 (shielded tube) Reverb return amplifier. 12AX7WB Russia Input Gain Stage 1 and signal splitter for both channels V2 Tone Control Driver, Drive channel 12AX7 China Gain Stage 3 for Drive channel V3 Gain Stage 2 for Clean channel 12AX7 China Gain Stage 2 for Drive channel V4 Reverb Driver. Small Signal Pentode EF86/6267 Not interchangeable with 12AX7 or EL84 V5 Phase Inverter 12AX7 China Power amp input stage V6 Rectif ier Tube 5AR4 Russia V7 - 10 Power Tubes EL84 Russia http://www.thestringnetwork.com Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.