Jmi ac30 tube layout software

Since vox is making primarily chinese junk these days, jmi has gone back to business and. Tubeset for vox ac30 6tbtbx the input tube for the. Find special audio and hifi tubes from leading brands like psvane or kr audio. Personally i have always proffered the sound of the non top boosted old jmi s that i heard not that i dont like tb models, far from it. The bass is heavy, the treble needs to be past noon to really start to give any real bite and the mids are nowhere near the spongy mids from jmi era amps. For brian mays 1998 world tour, we stuck with the standard issue vox chinese 12ax7s which sounded fine. Jmi made the amplifiers for the vox musical instrument company way back in the day. The cabinet build isnt bad but the only other expensive amp i own an afd is in a different league, ive no doubt cabinet manufacturer has improved vastly in the last 50 years. Two types of tube amplifier hum and how to determine the source duration. But i am lucky to have heard lots of beauties both in the studio and live, and stand out ac30 s for me were always 1old jmi s and 2 non top boosted.

The vox showroom vox ac304 four input guitar amplifier. Tube amp schematics, tube amp information, tube amp projects. The jmi amp 306 is a bit of a departure from the traditional ideas that many guitar players have of fender amps. Jmi ac15 single alnico blue combo amplifier hot rox uk. The heart of vox tone comes from the power amp section, and three key design concepts were combined in the ac15 power amp design to create the characteristic vox sound. Everyday low prices and free delivery on eligible orders. It was introduced in 1958 to meet the growing demand for louder amplifiers. The vox ac30 was designed and made original by jmi jennings musical industries. This is definitely solidstate, since its got a few effects, chorus and reverb, built in. If you want use ac30 in india with gsm sims, all that you need to install drivers and download dcunlocker software and purchase 7 credits using your paypal account approximately rs.

My first ac30 was an early 1990s korg model with blues, with the don butler mods mm ot, carbon comp resistors, better caps, filtering reduced to vintage levels it sounded pretty close to a mid60s jmi, but because i favor the semidirty ranges of ac30 sound i had to use a thd hotplate with it to be able to play anywhere. Review vox ac30 hw2x hand wired amplifier with brian may special guitar. This allnew ac30 represents the evolution of an iconic sound, pairing legendary vox tones with a simple, modern approach to amplifier design. The switch to the ac30 tube head proved more reliable, but as the audiences got louder, more power would be needed.

Since the ukmade reissues of the 1990s, the brand has been continually evolving its solution to affordableyetauthentic new versions of its number one son. Look at the chassis and see if it has a tube rectifierif so, it is going to be virtually the same as a jmi ac30. This monophonic, tube powered organ became a minor sensation in britain in the early 50sand put jennings company firmly on the map in the process. Hi luis, lets take a look at why a standby switch is included in most amps and see if your technician has given you some sound advice. They then went to a pcb contruction and got farther away from the jennings design. A standby switch was included as a feature on tube guitar amplifiers, not to give the player instant access to the amps performance mode, but actually for a much more important reasonthe preservation of the tubes themselves. Vox diagrams, schematics and service manuals download for free. Jul 16, 2019 far more significant to jmis growth, however, was the univox j5 electronic keyboard that soon followed.

The cabinet design uses the classic brown grille cloth, black tolex covering beigefawn option available, leather straptype handle and one 12 alnico blue speaker. Zte ac30 verizonunlocking or unlocked softwarefirmware. Hoffman amplifiers tube amp forum, vox ac15 layouts. The gibson ga70 tone circuit included one 12ax7 tube. The vox ac30 has always been considered a pure class a design, and is the first example offered when someone inquires about what a class a amplifier sounds like. Nov 03, 2009 amp is based on the 1959 vox ac304 amp witht he ef86 front end. I want to build, but have some other ideas too, an ac30 treble which a subcontractor for vox jmi did, westrex, a westex eble version. A significant watershed came in 2005 when vox switched production to china for the wellreceived custom classic series. The ac 30 tb to me, is both brilliant and a bit daft in its.

For ac30 s built in the 1960s jmi or 70s cbsarbiter, or 1980s rosemorris era the following preamp tube configuration applies almost all of them. Jmi later changed alnico speakers to ones made by tayden. Although the company makes guitars, it is bestknown for two iconic amplifiers, the vox ac15 and the vox ac30. Nice score to me lots of iskra resistors, quite a lot mustards, dogbone mica caps. He stalks the girl on the sides to allow them to fix the walls of amplifiers not present on the reissues. Alongside the tweed bassman and therefore plexiderived circuits, the ac30 is one of the mosttapped of the boutique amp era, while still appearing in many massmanufactured guitar amps as well.

The vox ac30 custom valve guitar amplifier vox amps. To connect with amp clone handwired guitar tube amplifiers, join facebook today. Jun, 2009 ive never owned a jmi, but ive heard and played through several. All of these pdf files are available for free download. But you can pull the chassis out and let the tubes cool in free air if you want. My ac30 is a brown one, and its been especially roadworthy. The ac30 went through some design changes during that time, not necessarily for the better. Buy a service engineers guide to the vox ac30 valve amplifier revised by grosvenor, stephen isbn. When the solid state t60 bass head proved unreliable, mccartney continued to use the t60 bass cab, but powered by a jmi vox ac30 tube head, which is pictured here on a chrome stand between johns amp and the drum riser. Vox ac30s1 30w 1x12 tube guitar combo amp black musician. The 1961 jmi vox price list offered the ac304 normal for. The fawn cabinets are so nice,mine look like 500 bar gigs.

In that case, id stick to the ac15 style power supply with the ez81 rectifier so that the voltages are correct. This jmi made english classic put it all together with many other ingredients to create a sound all its own, and a guitar tone for the ages. Apparantly these jmi reissues kick major tail, and it looks like they only have a few dealers in the us, and none are. Jmi offered two models of the ac304, one for normal frequency and a second for bass frequency. There are hundreds of pages of tube amp information on my library page. Discussion in amp central station started by filmix2, jan 7, 2011. One half of the tube was used for gain, the second half was a cathode follower to power the tone control circuit. Up for sale, a 1964 vox ac306 in excellent condition, complete with a pair of celestion silver bell t1088 model speakers. Vox everything is marked, and on the back it says jmi. You might also reconsider, but you already have an ef86 in another amp.

We have 2 vox ac30cch manuals available for free pdf download. The only differences between the ac304 normal and the ac304 bass were the values of seven capacitors in the preamp of the normal channel. Seems like thers a demand for amps with that early circuit with the ef86. Threedimensionality, depth and scale, diversification. Our focus is on backing outstanding software companies via capital investments, strategic advice, teambuilding, and proven value creation strategies. Ac30 top boost, a jmi product ac 30 top boost, dmi dallas musical industries, 19731978. This mean i cant guarantee proper functioning of attached layout. Mar 08, 2012 jmi era vox ac306 circa 1964 replica layout.

All tube design featuring two 12ax7 preamp tubes and four el84 poweramp tubes. Jmi designer dick denney approached the job with the guitars own sonic performance in mind, and the results speak for themselves. Please visit my tube amplifier forum heres the place you can go to ask tube amplifier questions. The power amp, employing a valve rectifier a gz34 and two el34s operating with fixed bias was probably designed at jmi, with input from triumph electronics.

By clicking on the image you get an pdf file, which can be zoomed in. Unfortunately it is not a complete class a amplifier, and the confusion stems from the fact that it is using cathode biasing on the output tubes. Characterised by its jangly highend sound it has become widely recognized by british musicians and others. The vox guitar amplifierand the ac30 model in particularhas played a. I did my layout from actual unit carried by my british friend his ac30 6 had 47nf cap at this position other reason is i seen no other ac30 6 with 5nf for c41 myself both in person nor on the web. Amp clone handwired guitar tube amplifiers is on facebook. Vox, manual services, hifi manuals, diagrams, owners. The vox ac30 is a guitar amplifier manufactured by vox. Its from the vox jmi period and its one of the first models with integrated topboost. Designed by dick denney, the tone of the ac15 became the sonic blueprint for all jmi vox tube amps to follow. Its singlechannel design is based on the revered top boost channel of the ac30, a sound that has been the. A service engineers guide to the vox ac30 valve amplifier. Hello there, im a long time lurker, first time poster. The second is v2, which is the second gain stage for the top boost channel.

I have not played the mastervolume hand wired series. Bear in mind im a passionate only, and im only getting started in tube world. Buying a vox amp page 2 steve hoffman music forums. I still have my 65 jmi ac30,but needed less power and weight for gigs. Jmi vox ac30 with top boost in panel the vox showroom. So i opened her upand wow looks like this amp hasnt been opened in a long time. Do you have a vox guitar or bass tube amp that needs repair or modifications. Ac30 vs ac15 output section is to taste but if you want it sound like an ac30 use the ac30 values other than cathode bias resistor and capacitor match that to the ac15 power section to keep the proper bias voltages. Eventually, a big uk music distributor called dallas arbiter they used to be the fender importer until fender set up their uk operation bought out the rights and starting making a few amps, and then korg bought out the rights. Dec 11, 2012 any thoughts on the vox ac30 custom classic. Hey jetset, it seems i ran into some guy in europe who takes jmi notopboost ac30s and converts them into ac304s. No glassy transparent top end that vox is known for. I was happy to see holly grail gray rs 32uf450v caps, but theyre fried, one is badly damaged with sings of burn, and the other one lacks of juice.

A lightweight, durable magnesiumalloy frame is used for the camcorder handle, increasing strength, and a large lens hood blocks light more effectively to reduce lens flare while permitting subjects to be seen from behind the hood. This well played and gigready ac30 sounds nothing short of spectacular, with the incredibly dynamic, touch sensitive responsiveness, smooth tube saturation, and glassy clarity that has made this amp one of the most sought after of all time. My ac30 is a jmi 64 and had a hard life before i had it but the fact that it still works and sounds amazing after 47 years should tell you something. Its ltspice, its a simulation software that i use to design a lot of circuits mainly pedals, with amps its great at predicting voltages, gain, what stages will clip at what voltages. Projects, mods, transformer diagrams, photos, sound clips. Also in my first post when i refered to v1 i was referring to the first valve what would make the first gain stage of the top boost channel and the normal channel. Website users have, and acquire, no right, title or interest in the information and images contained on, and downloaded from the vox website, other than the right to use the material from the download area for service. This one is before the solidstate rectified models, so this still has the gz34 tube, nos mullard ecc83s and el84s. Treble version, redrawed schematic and more text to be fallow. Many thanks to jim elyeas exhaustive tome vox amplifiers. The company is most famous for making the vox ac30 guitar amplifier, used by the beatles, the rolling stones, the kinks, the yardbirds, queen, dire straits, u2 and radiohead, the vox continental electric organ, the vox wahwah pedal used by jimi hendrix, and a series of innovative. Bear in mind im a passionate only, and i only get started in tube world. Here you will find our collection of vox schematics. Turret board order page tube amp parts, guitar amp parts.

Ultimate vox operation repair service manual schematics. A look back at the legendary vox ac30 guitar amplifier. Its five outputs guarantee connectivity to any input available. Vox amp heaven schematics berkley cambridge pacemaker. Up for sale, a 1964 vox ac30 6 in excellent condition, complete with a pair of celestion silver bell t1088 model speakers.

Manual services, hifi manuals, diagrams, owners manuals, schematics, datasheets and brochures online for free download for your guitar amplifiers, mixers, effect processors, midi synthesizer, available on of the vintage hifi site. The very early vsl amps were identical to the last jmi ampsthe first change was to a solid state rectifier. The vox ac30 custom valve guitar amplifier draws from over 50 years of tube ampbuilding expertise to offer the most versatile ac30 design in vox history search open search box or submit search facebook instagram twitter youtube soundcloud. Tube amp schematics and layout diagrams everything from acoustic to wurlitzer pdf tube amp books that you can download right click on the links below and then choose save target as. Electro harmonix replacement tubes kit for the vox ac30c2. You will get the message that, your unit is unlocked. Artists including the beatles, the edge from u2 and brian may from queen have famously used these amplifiers both live and on recordings. I have had the opportunity to play this amp several different times in different settings. Ac30 poweramp section of the top boost reissue 1993 onward, download diagram.

Im not technical, but our guitar techs keep an eye on things, and sometimes theyll say, sounds like your tube is getting weak and ill say, ok, change it. Over the weeks it sat on my bench, it tested all my skills and taught me a great deal about the vox design. The ac30 normal channel has a very clean low distortion preamp section and requires a 12ax7ecc83 that is not a high gain type, but above all has low microphonic characteristics. The ga70 tone control circuit is shown in figure 1 lower left, the vox top boost circuit in figure 2 lower right. The guide has new schematics, layout drawings, photographs and parts lists for the vox ac30,vox ac15,vox ac10,and the vox ac4. Jmi ac15 single alnico blue combo amplifier this is a detailed replica of the original 196162 jmi 15 15watt combo. I would like to bring to your kind attention that the ac30 chassis and faceplates are available at uk uk based retailer. The original firstgeneration ac30 used a gz34 tube rectifier, three ecc83s.

Singlechannel design inspired by the ac30 s trademark top boost. The vox ac30 custom valve guitar amplifier draws from over 50 years of tube ampbuilding expertise to offer the most versatile ac30 design in vox history. Above, a detail of the tone circuit of the ac50, and below it, the topboost circuit of the ac30, designed in 1961 borrowed by vox from the gibson ga70. Sounds like a vox ac15 crossed with a fender princeton. The ac306 replaced the troublesome ef86 based preamp circuit from the ac15 and ac304 with a new design based on ecc83 12ax7 tubes. I have a ac30cx2 and the bass and treble frequencies arent close at all to old jmi specs. Replace the missing pre amp tube and make sure that all of the channels work correctly. Axe fx ii amp of the week page 2 fractal audio systems forum. I would like to replace some of the tubes and need some advice. Since vox is making primarily chinese junk these da. A grid of anything, as launchpad tool lets you play in new ways create. Sections include 1 the history of vox, set against the larger history of guitar amplifiers and british and american music. Vintage 19651967 vox ac30 topboost page 2 the gear page.

Here is a clip of a jmi ac15 amp on clean tone which is close to what i am building. I always thought they should have made the tube top plate of perf metal and put a small quiet fan underneath, but that wasnt done. I was going for a u2 tone because i found out that the edge played a vintage vox ac30 top boost. Is built extremely solid in a rugged stainless steel housing and features comprehensive control layout. If i can sneak in an ef86 to build an ac304 i will but upon reflection think that to drill out an original vox 6364 or so,jmi chassis to accommodate the extra preamp tube ef86 might not be prudent.

Vox ac30cch manuals manuals and user guides for vox ac30cch. Mar 25, 2014 h3 ac30 custom seriesh at the 2010 winter namm expo vox introduced the custom series. The guide was originally intended for the use of service engineers, however it has also proved to be very popular with vox ac30 owners and enthusiasts. The originals had a really neat layout, but the heat rejection was poor. Vox is a musical equipment manufacturer founded in 1957 by thomas walter jennings in dartford, kent, england. If i can sneak in an ef86 to build an ac30 4 i will but upon reflection think that to drill out an original vox 6364 or so, jmi chassis to accommodate the extra preamp tube ef86 might not be prudent. A very thorough going over of a vox ac30 top boost from around 1970. Aug 23, 2016 the ac30 weighs just over three pounds. The tube amp library of information click the link above for tube amp info, schematics, board building information. Unlike the two channel, four input ac30 4, the ac30 6 was a new and unique design by lead vox engineer dick denney that had three channels and six inputs. Get the guaranteed best price on tube combo guitar amplifiers like the vox ac30s1 30w 1x12 tube guitar combo amp at musicians friend. If you want to know what vox is up to nowadays, check out the vox amps site.