group "buy/effort" for 12ay7 upgrade?

[creature.of.habit]

hi everyone..

sorry if the title created some confusion or whatever..i'm thinking about some stuff that can be done to our 12ay7s. lots around here i'm sure, i have 2 myself...

personally, i'dd be very very interested in turning mine into a rack unit, with some transformers, maybe at the output stage only, i frankly dunno what i can afford yet. what i do know is that i want to get rid of the weird power supplies that hardly hang in there, and i want them to be able to deliver a little more gain. other than that i love mine as they are.

this pre, for what it is, is perfect for me, but i'dd like it enhanced. the basis is done i guess, the biggest trouble i can think of would be the power supply...

i guess that, if people "unite" for this, we have a better chance at getting good deals with transformers, parts, cool chassis, etc, and also have a decent chance of getting someone to put these together at affordable rates. personally, i know i don't have the skill to do this so i really need someone to put everything together.

basically, i'm just throwing this out there to see if you guys are interested in it as well. i can't afford any of it yet, but will be able in a few months i think. so if there's interest, we can all def. start talking about it and sorting the whole thing out.

i know the lack of posts about them recently can only be indication that everyone's as happy with theirs as i am with mine. but still, don't you guys ever wonder what it could be like if this thing had the "right" components surrounding it?

what do you guys think?


diogo

[Wilkesin]

Im hoping to pick one up in the next month or so...I'll definitely keep my eye on this thread.

[BeepBeep]

At one point I emailed the folks at Funk Logic about the possibility of some sort of rack for the EH 12AY7 thinking it could be a good product for them (and something that I wanted), but they poo pooed the idea. Keep us posted on what you come up with.

[Recycled_Brains]

what i do know is that i want to get rid of the weird power supplies that hardly hang in there

that's my biggest gripe with it really. love the way it sounds. it would be nice to have it rack-mounted. i remember a thread a while back (probably in the DIY section) where someone had racked it.... looked really nice. maybe he'll chime in with some info.

i like all of your ideas creature.of.habit. i'll be interested to see what comes up on this topic.

-ryan

EDIT: i just found this thread: http://messageboard.tapeop.com/viewtopi ... ight=12ay7

[creature.of.habit]

but they poo pooed the idea.

sad to hear that BB :/

[creature.of.habit]

that's my biggest gripe with it really. love the way it sounds. it would be nice to have it rack-mounted. i remember a thread a while back (probably in the DIY section) where someone had racked it.... looked really nice. maybe he'll chime in with some info.

i like all of your ideas creature.of.habit. i'll be interested to see what comes up on this topic.

-ryan

EDIT: i just found this thread: http://messageboard.tapeop.com/viewtopi ... ight=12ay7

hey ryan, thanks for that.

i remembered the thread that trodden posted as well, dunno why it didn't pick up. despite not really liking the power supply concept and really wanting a more powerful one custom built for this, trodden's power supply alternative might just be a lesser evil worth considering. it's a great idea i think, in case this can't be sorted out.

i was also thinking of some sort of on/off switch. i added one to my dbx128, it's right on the cable, like a normal lamp, but i think we would want a rather more serious/professional way of doing it, in this case. i know most folks disagree with the on/off thing on tube gear, but if i had to guess, most guys here have them plugged to some sort of multiplug thing (right?) with several other things that need to be on when the 12ay7s don't.

[creature.of.habit]

i'm talking to this place...i'm sure they're rather expensive, but i'll hear what they have to say:

http://www.akzent-audio.de/e_index-pages.html

i basically asked them everything i wrote about on the first post. will post their answers.

the ideal would be one of us be able to take on all of the work for some money. idd gladly do it, if only i had the friggin skills :/

i think that, if we do this within ourselves, except parts of course, costumizing chassis, etc will be much easier. whereas, if we take this to some comercial place, every little detail will add up i guess.

either way, i'll see what those folks have to say. if this were to happen with the german folks, idd gladly receive all the preamps and ship them again from here if needed.

i'm also thinking of racking a black and a white finger together..

[creature.of.habit]

guys,

the german contact is yielding some great results, they will need a schematic though...anyone know where we can find this? i've tried emailing EH in the past, and i never got a reply. i'll try to PM analoghacker but i haven't seen him posting here in a while..i also think we can get a great discount at the german store doing this as a group.

i'm also talking to the person that racked Joel's EH White Fingers, and he's really a very nice fella. Now it's a matter of listening to what each person can do for us i guess.

anyone know anything about transformers and their specific caractheristics...especially how would they affect/work with the 12ay7 tone, and what would be our best choice/preference?

[dgrieser]

I think in one of the threads, analoghacker talked about adding in a second power supply so that there wasn't such a drain from the phantom power. I'd be interested in that. Would also like to have in racked. There was some talk about a 2 or 4 channel unit that was in a rack mount but that may have just been wishful thinking.

Don't mean to hijack, but I'd also like any tube recommendations for just clear/clean reproduction of acoustic instruments.

[creature.of.habit]

There was some talk about a 2 or 4 channel unit that was in a rack mount but that may have just been wishful thinking.

an urban legend by now

i wish those folks leaked anything about that actually, but it's not happening, god knows lots of people tried to get something out of analoghacker in the early 12ay7 threads and failed. i just hope those guys are busy with that!

[trodden]

I'm definitely interested in this.

I still need to get a 20 db pad to put in front of mine. It doesn't seem to like really loud guitar amps.. so i've mostly been using it on vox and room mic.

[KennyLusk]

Don't mean to hijack, but I'd also like any tube recommendations for just clear/clean reproduction of acoustic instruments.

NOS RCA's, GE's, and Sylvania's (AY7's and AU7's)

Tesla/JJ's are very clean also. Very low microphonics.

[lightandmind]

I just came across this, http://mixguides.com/studiomonitors/Bas ... -monitors/
and in the bottom section, the author discusses Ferrofluid, (in the "REAL MAGIC (NOT SNAKE) OIL" section. A driver modification that's definitely worth taking a look at. I am making a separate post in DIY to find any further info.

[creature.of.habit]

guys,

i'm getting great feedback from Bradley, the nice fella that worked on Joel's White Fingers. sadly, he doesn't have time to take on this work for us, but he has pointed out some valuable considerations, especially in terms of transformers...i'll post some of if here, i'm sure it's fine.

It sound like you need to do some experimenting first. Transformers
aren't distortion boxes or effects, generally they are transparent
unless you drive them very hard. You should look around for some
varied 1:1 transformers. The EH pre was designed not to need
transformers, so you need 1:1 ratio transformer. I'd give this a try
first, to get a good idea of what transformers are going to do for
you. And often nice, big vintage transformers are quite uncolored....
you may want to look at some edcors, or OEPs, something cheap and
crappy. Could be fun to try.

http://cgi.ebay.com/SMD-600-OHM-600-600 ... dZViewItem

you'd surely saturate something like this with the output of the EH pre.

i had no idea about this..you live and learn i guess...i thought pres were either (generally) transformer or transformerless..and that pretty much anything could benefit from great, big transformers (where justifiable of course)! turns out, i guess not...i have no idea of what this small component can do for us, or if you guys have interest in this..but to me, this is turning out to be more of a matter of racking this thing very well while isolating the 2 pres from the power supply effectively, and, at most, build a new internal power supply and the on/off switch, which is a must for me..

haven't heard back from the german company..

you guys tell me what you think ok?

gonna try and reach analoghacker about the power supply thing.

(edit: done.)

[creature.of.habit]

found some old quotes from analoghacker that might be of use now...

there is 10mA of phantom supply (48V) available in the 12AY7 mic pre. if the BLUE LED goes out, you are drawing more than 10mA. 10mA is standard... most mixing board phantom supplies are calculated for 10mA per channel, so they have alot more available for one hungry mic and who would know otherwise. older mics use much less current than newer ones, why i don't know.

the connector is called a "2 pin DIN". there is a simple and seriously important reason for making it a different connector from the standard "barrel" type power jack. i really don't give a shit what anyone else thinks when safety is a consideration, so if there's anyone out there who hates it, you're welcome... but it won't change a thing. the wall wart for the EH tube pedals is an AC supply, not a DC supply. were someone to make the mistake of plugging one in for the other, either nothing happens or it totally cooks your pedal permanent. we use a wide range of power adapters for our pedals, everything from 9V to 40V DC and 12V AC. there are real and important reasons for this that have to do with function. if we were to use the same connector for all of them, we would have a great deal more whining from certain corners than we already do... like i said, its simple and serious. you don't like it? buy boss.

you can remove the DIN connector and use any connector you want. i just wanted to explain why the DIN was there in the first place. yes, 16 VAC is a bit high... it would probably work for awhile, maybe quite awhile. but eventually the heater regulator would heat up too much and the thermal safety would kick in... turning off the pre. it would then cycle on and off (thats how you would know it was the heater regulator

the addition of a transformer coupled DI box does make this unit more flexible and you can easily understand why so many people go crazy about transformers. it makes connection issues go away at some small sonic penalty or shift. but you also understand the savings in cost by eliminating the trannys.

yes the blue LED goes dim or out with certain condensor mics (the marshall, for example...). this does not effect the operation of the pre. it does show you how much sag the wallwart has when you add the draw of the phantom supply. this is the one area where the economy of the unit is apparent. i accept the responsibilty completely. if you can replace the 12VAC 1A wall wart with a 12VAC 2AMP supply, this will "fix" the lamp and the bass will be punchier too.

the sag of the wallwart can be prevented by increasing the current available... however, that will only get you so far because there is another transformer inside to step up the voltage to over 200 volts... it isn't going to get any bigger. so there is only so much current available. because the phantom supply is derived from the high voltage supply in this design, the demands of the particular mic will determine how much current is drawn from the wall. older condensor mics draw very little. modern FET/transistor models draw more because of the preamp circuitry. in this mic pre, the phantom supply can draw more current than the amp does... because one supply is used to generate many voltages (for the different functions of the preamp), what affects the one, affects the many. this is why using a wallwart with more available AC current can help... but only so much. and it will NOT radically alter the sound. thats the point! but you might get a little more. it depends on how much effort you want to put into a $200 pre. the tube rolling will probably be more immediate and you can voice the thing for your own taste.
jc

and here's what some fella did with his:

The EH pre has two main circuit boards which are connected by a ribbon cable. There is one circuit board for the tube pre section and one for the knobs/LED's. I went to my local electronics store and got the parts to make a ribbon cable with the same number of pins as the EH pre with one female connector and one male connecter (basically a ribbon cable extender). It cost about 6 bucks. Using this I was able to mount the knob board on the faceplate of my rack chassis and the tube board on the bottom of the chassis (perpindicular). You can use the original case for the pre as a template for drilling holes in the new faceplate of the new chassis for the knobs. I made short XLR cables which go into the pre's existing attached XLR connects and then go out the back of the chassis pigtail style (or even better you can connect the other end of the cable to a surface mount XLR connector (2) mounted on the back of your new chassis. You have to use a 3 space (!) rack in this config because the tubes are kinda tall.

http://www.b-oz.com/ehpre.html