VOX AC-10 SRT or UL710 layout somewhere out there?

[SamVanLaningham]

VOX AC-10 SRT or UL710 layout somewhere out there?

Hello EL34’ers - I am looking for an AC-10 SRT (not twin or any other variant) layout and wiring diagram. Or even connecting with someone who's built one that can offer some build pics and info would be great!

I have not yet developed the skills to go from schematic to layout (would love to learn and I might have to, to get this one done - Im up for the challenge????). I have built one amp back around 2004, a 59' Bassman (5F6A push-pull 6V6 from Tino Zottolas books - pics below) with parts bought from this website even! It is an awesome amp, has been pretty reliable (I did fortify the super thin sheet metal chassis I made). This was one of the most rewarding things Ive done. I now spend most of my time building acoustics mostly but electrics as well.

I have read some other threads out there about the AC-10 SRT, (for example

https://www.thegearpage.net/board/index.php?threads/anyone-build-a-vox-ac10-srt.1851471/
http://el34world.com/Forum/index.php?topic=21791.0

and gleen that the schematic has an error or two, that the reverb channel isn't good, and that the thing that separates this amp from the other ac-10s is the ECC83 front end instead of the EF86 (though it seems the oscillator channel still uses that?). I see and it has been said that this amp most closely resembles the VOX UL710, which I’d build if no SRT info comes up or there were better layouts and wiring diagrams.

I also found some excellent photos of the insides of an AC-10 SRT here on this photobucket album: http://s889.photobucket.com/user/vox75/library/ac-10%20SRT?sort=3&page=1

I, like many others, am inspired by youtubers Doug and Pats AC-10 SRT. An additional concern is that their amp might have been modded a bit by Bryan Sours (http://www.mylespaul.com/threads/nrvad-vox-ac-10srt.380402/). But thats of less importance.

So I don't know if I have the skills to get there. But after reading many of the threads here, seeing Sluckeys layouts of the AC15 etc, Im reaching out to you guys to see if you can help.

OK take care. Sam




sams_cab&head by Sam Van, on Flickr

bassman&2x12cab by Sam Van, on Flickr

bassman_bottomview1 by Sam Van, on Flickr

[kagliostro]

Have you interest only in the AC10 SRT version or also the AC10 is of your interest ?

As you say, the SRT version has an inusual reverb and the alternatives are to build your own tank

or to modify the schematic to use a standard reverb tank

Franco

[SamVanLaningham]

Hello Franco. Thanks for the comm. I saw a thread or two of yours regarding an ac-10 build. Sounds like you had success!

Anyways, yes I only am interested in the ac10 art or ul710. I hear something different in these amps than the well known classic  ac’s.

I think where I might get to is having to develop and circuit layout and wiring diagram etc myself, which sounds difficult and potentially fun.

Sam

[kagliostro]

The layout is one of the diifficulties steps

the bigger difficulties, to me, is to rebuild the Reverb Pan, VOX used this kind of reverb unit, not the "standard" Hammond/Accutronics







I think that the fact you don't find AC10 AST clones is due to the difficulties about the Reverb Pan (Tank)

the easiest way to solve the problem that I see is to modify rhe reverb circuit as to be able to use an Accutronics tank

if you want the AC10 (not SRT, the EF86 - EFF82 version) Layout (L chassis) I can send it to you

Franco

[SoundmasterG]

R.G. Keen (Geofex) has a preamp board for the UL hybrid Vox amps. I am not sure if he has them for sale yet or if they were still in prototype form. I was working on this with him and helping to revise the instructions/building the circuit, etc., but I ran into some problems with job(s) and had to take a break from that project, and I still haven't gotten back to it. The only issues that I was seeing with building it was figuring out a solution for the reverb, and the tremolo also. I was able to source an original trem roach for those but I haven't tried to use it yet. There is a guy in England who build a clone of a UL730 using R.G.'s board, but I am not sure what parts he used for those circuits. Anyway, if you were interested in it, you could contact R.G. Keen and see if he is willing to sell you a board for the UL amps if you want to go that route. You would have to build the rest of the amp yourself (tube power amp, power supply, chassis, etc) and you would have to find transformers to supply the voltages you need for the power amp and the solid state preamp. If you are a novice that may be beyond your skills at the moment since there isn't any kit for this setup.

Greg

[kagliostro]

I was thinking to your idea and looking to the schematic


really, I think that before to draw a layout that schematic must be redraw


it is too tangled and this is a further difficulty to translate it in a layout


Franco

[SamVanLaningham]

Yeah Greg thanks for the info! this is waaaaaay above my pay grade:). I don’t need that big of a challenge:). As well, I think my bassman sounds great (just did a YouTube trying to demonstrate dynamics of a wolfetone p90 that’s going in a new build, here’s link for those interested)

&sns=em

Ok Franco! I think I would like to build an AC10 then and would love to try your layout/diagrams. I may have already seen and downloaded them if you had them in your thread????

Ok thanks everybody.

Sam

[SoundmasterG]

Sounds good Sam! Wolfe makes some great pickups! I've known him for decades and have the 2nd pickup he ever rewound around somewhere. Glad you're enjoying his creations.

Greg

[kagliostro]

SamVanLaningham

you have a PM

Franco

[SamVanLaningham]

Sounds good Sam! Wolfe makes some great pickups! I've known him for decades and have the 2nd pickup he ever rewound around somewhere. Glad you're enjoying his creations.

Greg

Way cool Greg! I’m becoming a huge Wolfe fan. The bloom in this p90 is excellent to my ears. Are you a Seattle guy as well?

For my new guitar build this pickup will be in the neck and a Monty’s of London PAF in the bridge.

Cool. Sam

[SoundmasterG]

Sounds good Sam! Wolfe makes some great pickups! I've known him for decades and have the 2nd pickup he ever rewound around somewhere. Glad you're enjoying his creations.

Greg

Way cool Greg! I’m becoming a huge Wolfe fan. The bloom in this p90 is excellent to my ears. Are you a Seattle guy as well?

For my new guitar build this pickup will be in the neck and a Monty’s of London PAF in the bridge.

Cool. Sam

Hi Sam, No I'm in Portland area but I do have relatives in and around Seattle so I get up there here and there.


Jason Lollar makes excellent stuff and is up your way also.
http://www.lollarguitars.com/


The most accurate vintage stuff to my ears is Dave Stephens of Stephens Design, but he has a waiting list and his stuff is more expensive than most. His website is sort of out of date, but all his latest stuff is on his youtube page.
http://www.sdpickups.com/
https://www.youtube.com/user/SDPickups/videos


I wish I had more time to build amps and guitars but am stuck just reading and commenting on forums for now. 


Greg

[SamVanLaningham]

Ok Franco has sent me the ac10 layout and wiring diagrams. Thanks so much! In case anyone is wondering why I flipped so easily, I originally started out just wanting an ac10 but then got the bug for the srt and 710. However, I was already on thin ice even considering building from a difficult to interpret schematic. Then Greg’s post clarified how out of my league this endeavor would be.

 So Now I gotta do it. I’ve actuslly thought of buying parts for two, building 2
and selling one to pay for both:). Crazy? Rationalizing? There are many tools in my shop that were bought for the “business”. And then who knows......they could sound different enough that I want to keep both hehe.

 Greg, sorry for confusion as I’m in Oregon as well, bend. I worded my question oddly due to thinking you lived in Seattle area like Wolfe:).

Just checked out Stephen designs. Wow they do sound good. Great even. But his confidence on being the holy grail is sort of intense for me to digest! What do Doug and pat think? I would have guessed they would have reviewed his pickups?

Sam

[SoundmasterG]

Ok Franco has sent me the ac10 layout and wiring diagrams. Thanks so much! In case anyone is wondering why I flipped so easily, I originally started out just wanting an ac10 but then got the bug for the srt and 710. However, I was already on thin ice even considering building from a difficult to interpret schematic. Then Greg’s post clarified how out of my league this endeavor would be.

 So Now I gotta do it. I’ve actuslly thought of buying parts for two, building 2
and selling one to pay for both:). Crazy? Rationalizing? There are many tools in my shop that were bought for the “business”. And then who knows......they could sound different enough that I want to keep both hehe.

 Greg, sorry for confusion as I’m in Oregon as well, bend. I worded my question oddly due to thinking you lived in Seattle area like Wolfe:).

Just checked out Stephen designs. Wow they do sound good. Great even. But his confidence on being the holy grail is sort of intense for me to digest! What do Doug and pat think? I would have guessed they would have reviewed his pickups?

Sam

Sam,


Cool that you are in Bend. I don't get down that way too often but its a nice place!


Dave Stephens can come across sometimes that way...some people think he is overconfident, etc. But a bunch of builders have stolen his methods and verbiage that he has shared from his website and his posts on Ampage pickup forum, and every review of his pickups has verified that they have the sound and feel of the vintage PAFs, so the proof is in the pudding I guess. I've known him personally for around 15 years (we used to go to a local blues jam for 10ish years until the venue closed up) and he's a great guy who is humble but when you know you have the answer, it isn't really bragging to be confident in what you have created you know? I don't remember if Doug and Pat have reviewed his pickups or not....I think that they contact the builder first to see if the builder wants them to review the product, and often ask to be able to keep the product as part of the review, at least in the case of new stuff. They are a unique and acquired taste and many people don't like their schtick, and Dave doesn't really like them much so I think he declined their offer of a review. He's been reviewed in Tonequest Magazine, Guitar Connisour, and others, including Dave Hunter who writes many guitar, amp, and pickup books, and articles for mainstream magazines like Vintage Guitar. Mr. Hunter purchased the pickups he reviewed for himself too, if that tells you anything. There are some well known pros that have used the pickups from Dave too, such as Billy Gibbons from ZZTop, one of the Anthrax guitarists, the current lead singer for Alice in Chains, Mick Grabham from Procul Harem fame, etc. I should also qualify what I am saying about his products by mentioning that I own one of his PAF style sets and two Tele sets and I also own some custom Strat pickups and P90's from Wolfe and some pickups from Jason Lollar also, and for my live playing I tend to use the ones from Dave Stephens the most. I'd like to get more but they are expensive and I'm poor. :)


So regarding the amps, are you saying you plan to build both the AC10 SRT and the UL710 now? Or you're just considering it? Steven Walsh is a guy in the UK that I know who has built a clone of the UL730 series using the board from R.G. and you can see it/hear it in this video.

Q95fw


The UL hybrid amps have a unique sound and are the sound of the Beatles Revolver and Sgt. Peppers but they aren't for everyone. They also need a power supply that can supply the voltage requirements for the tube and solid state circuits, and they need to be made in such a way that the solid state parts don't get too hot since they are in a chassis with hot tubes. Building that would require some careful thought and layout and parts choices. Also, the Vox book by Jim Elyea is the bible for all things Vox. If you get the Deluxe version it comes with the schematics and they are all drawn well and easy to read. Here is a link to the book on Amazon, though I'm sure if the one I linked has the schematics or not. No time to look into it further but you can search further if you want.


https://www.amazon.com/Vox-Amplifiers-Years-Jim-elyea/dp/142431769X


Greg

[SamVanLaningham]

Oh man good stuff, Greg!

Re: stephens pickups. I was seeing him at least two ways, over confident and/or a guy who just feels passionate about having found some answers to a elusive question. Some of those guys can be really humble so I’m taking your word for it!

However, I don’t have $650 for the set either:). But I’m going to listen to them a ton today tonight. And then when I get my Monty’s of London PAF and build the guitar it’s going into, I’ll post a video and we can discuss! I listened to EVERY SINGLE “chasing Oscar” sound clip on Doug and pats site and decided the Monty’s were my bang for buck choice. The throbaks and Tom somebody expensive ones are sounded good.

Re: AC10. Sorry for confusion! I’m entirely skipping the srt or 710. Above my pay grade! I’m going to build an ac10 (twin I guess....the traditional one). But I was pondering building two identical ones and selling one:).

I just want a lower wattage amp that breaks up quicker than my 50w bassman.

Cool.

Sam

[SoundmasterG]

Oh man good stuff, Greg!

Re: stephens pickups. I was seeing him at least two ways, over confident and/or a guy who just feels passionate about having found some answers to a elusive question. Some of those guys can be really humble so I’m taking your word for it!

However, I don’t have $650 for the set either:). But I’m going to listen to them a ton today tonight. And then when I get my Monty’s of London PAF and build the guitar it’s going into, I’ll post a video and we can discuss! I listened to EVERY SINGLE “chasing Oscar” sound clip on Doug and pats site and decided the Monty’s were my bang for buck choice. The throbaks and Tom somebody expensive ones are sounded good.

Re: AC10. Sorry for confusion! I’m entirely skipping the srt or 710. Above my pay grade! I’m going to build an ac10 (twin I guess....the traditional one). But I was pondering building two identical ones and selling one:).

I just want a lower wattage amp that breaks up quicker than my 50w bassman.

Cool.

Sam

Yeah Dave's pickup sets are spendy, but since he hand makes mostly everything on his pickups including many of the metal parts, then it makes sense. Tom Holmes is who you are thinking of...his stuff seems to have a good reputation, but I haven't played them myself so I can't comment directly. Throbak and Dave shared some metal research costs and results with each other, but that was early on in the research and Throbak came to some conclusions that were great for marketing but maybe not for accurate sound. Some people seem to like his pickups though so there you go. We all hear differently.


RE: AC10 build, I think it is good until you get some more experience to build some more widely known and documented amps. Then once you have more knowledge and experience you can try to build the lesser known stuff and maybe some of your own designs. Another thing you might consider is to add power scaling to the bigger amp. In order for it to work correctly you need to add master volume also, but it allows you to turn the power of the amp down to even a half watt, and get most of the loud sound. It takes some dialing in to get it the way you want it, but its pretty cool. I've used it a couple times and I like it. You can find out more about power scaling at Kevin O'Connor's site and in his books.


http://www.londonpower.com/


Greg

[SamVanLaningham]

Thanks Greg. All good info. Yeah Stephens pickups do sound good for the listening I’ve heard.

Sam

[kagliostro]

SamVanLaningham you have a PM

if you decide to go on with the AC10 project, please, revise the layout with the schematic

and use this schematic to revise



Here is the Chassis Layout





Franco

[SamVanLaningham]

Franco! Thank you so much.

I just read somewhere that the difference between the 10 and 15 was one resistor. I haven’t looked deeply to corroborate but they do look similar.

Ok thanks again. Sam

[kagliostro]

..... the difference between the 10 and 15 was one resistor .....

may be .... but that didn't seems





oh, there is this 1959 AC15 version, but also here the schematic is difficult to be read quickly, try to see if they are similar



However I didn't remember the availability of a layout for that version of the AC15

Franco

[sluckey]

That AC-15 (NO. V-1-5) is the circuit I built a couple years ago. Several others have also built it. There's a layout on my website but it's nothing like the original layout. Hoffman offers a board for it.

[SamVanLaningham]

Thanks Franco and sluckey for the thoughts.

Sluckey, I came onboard here partly because of your thorough efforts! Nice to be a part of a forum with so many people that are ready to help.

I’ve also been talking now through email with an amp builder who pm’ed me thru tdpri. His thoughts and experiences are making me re think again! I’m wishing I would have come into this forum a little more prepared for what I really want to do, as I do not want to waste anyone’s time here. But I am indeed learning and very much appreciating the amp building brotherhood:).

Sam