http://www.award-session.com/pdfs/AS112A_Plans.pdf
for plans of the Marshall 18W 1974x 1x12" cabinet see above.
for plans of the Marshall 18W 1974x 1x12" cabinet see above.
logged in and found the download site with the plans and stuff. i think that VVR is going to come in handy with my plexi, glad i left a hole for it on the front panel.
btw., just got one of two PT/choke sets from signal. i've planned two 50W amps, an SLO50 and a 5f6-a tweed bassman. the PT is HUGE. monster. this will be a fun year
btw., just got one of two PT/choke sets from signal. i've planned two 50W amps, an SLO50 and a 5f6-a tweed bassman. the PT is HUGE. monster. this will be a fun year
Who is building these amps?
Where in Mumbai?
I can offer 2 18W Marshall 1974x builds (the amp build is what I do not have time for - the carpentry is easier for me to outsource (once I get the Birch Ply) and 2 EL34 PP builds that are left incompete for lack of time.
i'm building these amps didn't i mention that earlier in this thread? currently i'm rewiring my own modded 2061x build (the one where the chassis got "inverted") and also working on a souped-up soldano atomic 16.
south bombay, peddar road. although i will be moving my stuff to work (vikhroli) soon so that i clear out the evenings for making music and not building stuff for making music...
what are the EL34 builds? guitar or hi-fi?
didn't i mention that earlier in this thread? currently i'm rewiring my own modded 2061x build (the one where the chassis got "inverted") and also working on a souped-up soldano atomic 16. south bombay, peddar road. although i will be moving my stuff to work (vikhroli) soon so that i clear out the evenings for making music and not building stuff for making music...
what are the EL34 builds? guitar or hi-fi?
i'm building these amps
south bombay, peddar road.
what are the EL34 builds? guitar or hi-fi?
Oh yes you did but i figured so many amps? Where do you get the time?
Well I dont live far. Breach Candy but between work, family and other social engagements I do not get the time to listen to much music leave alone build stuff.
The EL34s are designed by Wayne (cogsncogs) from post 252 on this thread
http://www.diyaudio.com/forums/tubes-valves/69042-el34-schematic-confusion-26.html
http://www.diyaudio.com/forums/attachment.php?postid=811638&stamp=1136905599
http://www.diyaudio.com/forums/attachment.php?postid=509305&stamp=1100080737
It uzes 6SL7 (input), 6SN7 (splitter) and EL34s.
Wayne made some posts here
http://www.diyaudio.com/forums/tube...30w-ultra-linear.html?perpage=10&pagenumber=3
and Ray Moth's additional posts are here
http://www.diyaudio.com/forums/tubes-valves/68488-el34-pentode-push-pull-5.html#post779085
hi navin,
sorry, didn't check back on this forum and my notifications for a while.
let's just say i got a bit carried away ordering transformers. i'd like to finish the stuff i've started.
i too had toyed with the idea of starting my own tube amp biz, i'm just not so sure about it anymore. i do custom jobs on amps and pedals though.
as for time... i'm just 29, and haven't given in to the usual familial expectations that one would place on a 29 year old gujju..... yet! hence, i have a decent amount of time that i can dedicate to this passion.
life has been fairly busy in the last 6 months, so the building has been slow. i've been working on my plexi a lot, ordered some replacement pots cause i've had problems with the ones in mine. junky 16mm PCB-mount alphas.
i did, however, install a VVR. that thing is fantastic. i'm never building a vintage-voiced 18W-30W amp again without one.
let me know if you have the time and energy for 2 18W marshall amps and 2 30W EL34 amps. Of course we can start slow and do one amp at a time.
i'd love to take you up on that. slow sounds good, i'm juggling a few things at the moment. do you have all the parts, chassis, etc?
let me PM you my contact details. call when you have the time. cheers
what I have are the tubes, sockets, chassis, and OPTs. I have not bothered to collect the passive parts (caps, resistors, pots, etc..) or accessories like speaker terminals, RCA input sockets etc...
For the Marshall clone my carpenter can build the speaker cabinet and all you will be responsible for will be the amplifier. I will souce the speakers from Mohamed Ansar of BE3.
For the Marshall clone my carpenter can build the speaker cabinet and all you will be responsible for will be the amplifier. I will souce the speakers from Mohamed Ansar of BE3.
Hi Navin,
How well do you know the Miracle people ?
I bought one of their audio transformers, just to get a feel for their build quality.
It is made of 0.5mm non-CRGO steel!
That's just s**t. Even 230V mains transformers aren't made of such an inferior grade of steel.
Anyway, I'm waiting for some test equipment before I pass judgment, but I have a feeling the transformer is not going to meet their published spec (40Hz - 20kHz).
FWIW, i've bought twice from miracle. once it was a toroidal stereo set for a 2x EL84 stereo amp. the second time i bought 5 sets of 18W transformers (PT+OPT) as well as a single-ended one for a smaller amp.
keep in mind that i'm not an audiophile and still very much a newbie, but i liked what i heard on the single ended transformer. i don't expect it to match up to, say, a heyboer or mercury magnetics, but it sounded (and felt) pretty damn good on the guitar amp. the toroidal output transformers were well overspecced (25W for 2xEL84 ultralinear) and i quite liked the way they sounded, i'm going to be testing that amp again this week with new tubes in the preamp and listen again.
so far, i've been quite happy with the dynamics that signal transformers have given me. need a better guitar now.
eventually, once i have that kind of money lying around spare, i will buy better transformers (maybe not mercury, who are severely overpriced, but something like heyboer or pacific) for my amps and see how much of a difference it actually makes. just to be clear: i don't have a reference point, never used one of the more expensive imports because, well, they're expensive and i don't have the budget for a $150 output trafo yet.
however: i specified CRGO while ordering. i don't know how to actually tell if a steel type is CRGO from a visual inspection. do feel free to give me some pointers on this!
i have a habit of overspeccing my stuff. there's a bit more oomph and clarity in the lower end, or so i'm told.
PJP, are there any local winders you would recommend (guitar amps, i'm not so active with regards to hi-fi)? if so, who? call me cosmetically inclined, but i'm a bit partial to transformers with bell-ends/shells
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i use vishay/philips 1% metal film resistors, 0.5W and sometimes generic metal oxide plate resistors. i did use some carbon composition 220k resistors in my 2061x though, only in front of the PI section.
as for caps, i have NOS german film caps that i've used and sound pretty good so far. wild mix of EROs, WIMAs, some east german ones with the TGL stamp, and other oddballs. i did place an order for orange drops and mallorys recently, i want to see how the measure up against the good old stuff.
as for pots, i ordered some (nothing fancy, just the usual 24mm alpha pots) for a bunch of amps along with the caps, it'll be about 2-3 weeks till they get here though.
i'm assuming you only have the chassis ready for the 30W EL34 amps? or do you already have chassis for the marshall clones?
Yes I have the chassis of only the EL34 amps but making the 18W chassis is not a problem as there is enough information available on the internet about this amplifer. So that the amp does not look like an outright clone I do not intend to use the Marshall name on it and might use a different grill cloth (similar to the Studio 15 maybe)
Tube amp Chassis - Pedals-Boxes
http://www.18watt.com/modules/Gallery/albums/18watt-Plexi/Plexi_18watt_Layout4.jpg
http://www.marshallamps.com/downloads/files/1974X hbk.pdf
18 watt Marshall amp kit.
Replacement Chassis, Chassis Kit, Amplifier Chassis
http://www.18watt.com/storage/18Watt_Layout_Original.pdf
http://www.marshallamps.com/downloads/files/2009 catalogue.pdf
hi navin, sorry again for the late reply. got the notification on my phone and didn't check back at the forum later.
i've designed a few chassis the past and am getting a batch of them made in the near future; i just need to finalise all my designs and see if the fabricator's machines are up and running. so i could certainly throw in one more.
what would you rather get started with? the EL34s or the marshalls? seeing that you're halfway set for the EL34 amps, that may just be a better idea.
btw., did you get my PM?
i've designed a few chassis the past and am getting a batch of them made in the near future; i just need to finalise all my designs and see if the fabricator's machines are up and running. so i could certainly throw in one more.
what would you rather get started with? the EL34s or the marshalls? seeing that you're halfway set for the EL34 amps, that may just be a better idea.
btw., did you get my PM?
Actually my feeling is that since the Mashalls EL84 amp is standard it might be a easier place to start.
The only difference is I have a chassis for the EL34 but not for the Marshalls. Still making a chassis is not a big deal.
The EL34 amp is a fresh diy design (Wayne - congncogs has done most of the work, SY and others have helped) and I suspect it might be more diffcult to debug. I envisage porblems in 3 areas
a. power transformer - Output transformer hum (even though my power transformer is a torroid) as they are quite close
b. the single 6SL7 might mean poor channel seperation although this is part of the design since both channels are feeding different drivers in the same speaker (one EL34 amp for left channel one for the right)
c. making one channel in triode mode and one channel in UL mode is not something I have seen done before. On paper it should not be a problem but experience is a whole different game. My suggestion is to first wire the am in UL (both channels) then triode (both channels) test both modes and then try the UL-trioide combo. The reason for this is the triode channel will drive the tweeter and UL channel the midbass.
Oh yes I got your PM. Thanks.
Hi Navin,
In the forum you mentioned that audio tubes are available in Mumbai Local market. Where are they available? Can you give me some useful hint?
I used to do a bit of DIY audio when I was in school/ well high school. Thats long back in 80s.
Now after so many years again feeling ticklish. And right now I don't have any thing to start again. Thought I should first get some valves and transformers. I have been reading your post on and off, sometimes. So thought you may guide me. Tell me where to look for in Mumbai local market?
Well...... just bought a soldering iron and trying to figure out two amps using EL34 ( Picked out from a old store near my house in Chinsurah ( West bengal) ) don't laugh at me!!!!!!!!!
Cheers.
In the forum you mentioned that audio tubes are available in Mumbai Local market. Where are they available? Can you give me some useful hint?
I used to do a bit of DIY audio when I was in school/ well high school. Thats long back in 80s.
Now after so many years again feeling ticklish. And right now I don't have any thing to start again. Thought I should first get some valves and transformers. I have been reading your post on and off, sometimes. So thought you may guide me. Tell me where to look for in Mumbai local market?
Well...... just bought a soldering iron
and trying to figure out two amps using EL34 ( Picked out from a old store near my house in Chinsurah ( West bengal) ) don't laugh at me!!!!!!!!!Cheers.
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