Wonderlandaudio
Well-known member
They run positive to ground or as said, -24v
DIY DUAL GERMANIUM MIC PRE-EQ BASED ON NEVE EARLY DESIGNS
- Thread starter Wonderlandaudio
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Wonderlandaudio
Well-known member
I got the Gardners in China. In case the "discoverer" wants them please tell me.
Wonderlandaudio
Well-known member
It seems that the interest on the Gardners or the project has evaporated... Please let me know ( mainly the ones that had a reserve ) so I can offer to the rest or take a decission on what to do. Thanks
I'm definetly still interrested, but I find it a bit overwhelming to source the transistors myself since there's so much other stuff to source for other projects that I'm afraid this might end up as a shelf project unless you source the difficult components..
These are not the cheapest transfomers either.. especially for a shelf..
What do others say, I know we all want some germanium sound for our color array. Let's keep this thing going!
hejsan
These are not the cheapest transfomers either.. especially for a shelf..
What do others say, I know we all want some germanium sound for our color array. Let's keep this thing going!
hejsan
Wonderlandaudio
Well-known member
It was going to be a shelf project , basically a limited run from my own company. Eventually everybody wanted Gardners to the point I offered my own 1055 and 1253 Xformers. I offered all of you to get a quotation on Gardners and take 20% out. Nobody replied....
If I have to source everything but resistors and solder.... I´ll send the Gardners that are already sold ( I mean, paid ) and would help all the others with any clues or sourcing or whatever they may need.
Some of you really interested contact asap
If I have to source everything but resistors and solder.... I´ll send the Gardners that are already sold ( I mean, paid ) and would help all the others with any clues or sourcing or whatever they may need.
Some of you really interested contact asap
[quote author="Wonderlandaudio"]It was going to be a shelf project..[/quote]
Oops, by shelf project I meant a project that would be forgotten on my shelf, I didn't know that was a term used for something else..
But I'm really interested still.
Oops, by shelf project I meant a project that would be forgotten on my shelf, I didn't know that was a term used for something else..
But I'm really interested still.
Wonderlandaudio
Well-known member
You meant ... as a yourself....project and I understood ... as a myself...
Anyway to convert this in a oneshelf project is by no means my intention and, if I have to do all the hard and expensive work, like ordering transistors in bulk quantities, Carnhill Output Xformers, Boxes, Making a front and back plate, redesigning the EQ stage, sourcing the tube like octal sockets. knobs, switches, etc.... That´s what I usually do when launching a new product. Cant see the difference...
Anyway to convert this in a oneshelf project is by no means my intention and, if I have to do all the hard and expensive work, like ordering transistors in bulk quantities, Carnhill Output Xformers, Boxes, Making a front and back plate, redesigning the EQ stage, sourcing the tube like octal sockets. knobs, switches, etc.... That´s what I usually do when launching a new product. Cant see the difference...
AudioHammer
Well-known member
I am interested. Let's keep this thread going.
Wonderlandaudio PM me if you have two Gardners left.
audiohammer
Wonderlandaudio PM me if you have two Gardners left.
audiohammer
Wonderlandaudio
Well-known member
Ok, some of you got the Gardners elsewere, which, in fact, let me follow with my limited run and complete de DIY project.
Let´s put it this way:
This is the easier of the easiest. It only requires some organization on who´s gonna get what and that´s it.
I´d restringe the Gardners I´m parting out with to, 6 pairs. This means Thomas Kristiansson, Joel Cameron, Baumann and 3 or 4 more.
The first 3 or 4 paypals ( confirm 1st ) will get them. As API knows there´re more around so, up to you.
Let´s put it this way:
This is the easier of the easiest. It only requires some organization on who´s gonna get what and that´s it.
I´d restringe the Gardners I´m parting out with to, 6 pairs. This means Thomas Kristiansson, Joel Cameron, Baumann and 3 or 4 more.
The first 3 or 4 paypals ( confirm 1st ) will get them. As API knows there´re more around so, up to you.
Wonderlandaudio
Well-known member
Can be done the old way, by hand, no cads
AudioHammer
Well-known member
I found some Gardners in the US. Now on with the DIY project.
tommypiper
Well-known member
Guys, I've read this thread carefully. But I'm still confused a bit what's going on. Can someone explain?
1) Gardeners. Why are they important to this project? Is it simply that they were used with that vintage and you want to stick with the originals if possible? Couldn't one use anything else?
2) Are you planning to do a group buy on the Ge transistors? I've seen some concerns about sourcing and various ideas. What is the plan?
3) Is Wonderland planning to make a pcb?
4) Is Wonderland planning to make a kit, with faceplates, etc?
cheers!
1) Gardeners. Why are they important to this project? Is it simply that they were used with that vintage and you want to stick with the originals if possible? Couldn't one use anything else?
2) Are you planning to do a group buy on the Ge transistors? I've seen some concerns about sourcing and various ideas. What is the plan?
3) Is Wonderland planning to make a pcb?
4) Is Wonderland planning to make a kit, with faceplates, etc?
cheers!
Tekay
Well-known member
Redrawed versions of all the schematics are on the way, including the B105 and the 1057 channel amp which have switchable low / mid frequencies and a HP filter, just need to check them first.
Wonderlandaudio
Well-known member
I¨ve sourced the Ge transistors. Different options here. Designed a frontplate. Collected some original black pointer knobs. Although I´d redraw the original cards and fill them up. If we decide on a standarized design I could ask my provider for a box with all the metalwork to fit the cards and transformers in.
Sorry, I've been on the road working on a film for over a week and have had virtually no internet access and have not been able to follow this or make a payment. I'm still interested in this project, but the main question I have is regarding the differences between the Gardner transformers that you have and which ones I would need for this project. Looked at the schematic, but some of the model numbers are not clearly legible.
Obviously the MU7529 is the mic input, but is the MU7524 or the MU7525 the output? I thought that the LO1166 was the output. It seems that the line in on the schematic does not have a transformer. Is that the case?
Lastly, has anyone thought of sourcing inductors for the EQ's?
I am interested in putting together two channels of these.
T
Obviously the MU7529 is the mic input, but is the MU7524 or the MU7525 the output? I thought that the LO1166 was the output. It seems that the line in on the schematic does not have a transformer. Is that the case?
Lastly, has anyone thought of sourcing inductors for the EQ's?
I am interested in putting together two channels of these.
T
Wonderlandaudio
Well-known member
We were thinking for the DIY project not to include mid band eq to keep it simpler.
Regarding the transformers, All 7424, 7525 and 7529 were used as mic input xformers in one or another model. The output is the LO1166.
As this became as a stand alone dual mic pre I never thought a line input was to be used. Line input on the 1055 is unbalanced. 1057 and 1058 are balanced and would require a 10K/600 Gardners. Model number I cant remember nor have any in stock.
Then I purpose the inclusion of the Baxandall EQ, which puts one B101 or B105 to play. Would be more interesting not only soundwise but buiding it.
Regarding the transformers, All 7424, 7525 and 7529 were used as mic input xformers in one or another model. The output is the LO1166.
As this became as a stand alone dual mic pre I never thought a line input was to be used. Line input on the 1055 is unbalanced. 1057 and 1058 are balanced and would require a 10K/600 Gardners. Model number I cant remember nor have any in stock.
Then I purpose the inclusion of the Baxandall EQ, which puts one B101 or B105 to play. Would be more interesting not only soundwise but buiding it.
[quote author="Wonderlandaudio"]
1057 and 1058 are balanced and would require a 10K/600 Gardners. Model number I cant remember nor have any in stock."[/quote]
To make this more apealing to people, if you would be interested, it would make more sense to make this as accessable to more different transformer layouts other than a Gardner. You could use any 10K/600 transformer of course. I'd be very happy to have line inputs with transformers on these.
[quote author="Wonderlandaudio"]Then I purpose the inclusion of the Baxandall EQ, which puts one B101 or B105 to play. Would be more interesting not only soundwise but buiding it.[/quote]
Please elaborate on a Baxandall EQ. Did a search and read a bit about it, but would like to hear something in layman's terms if possible.
Cheers,
T
1057 and 1058 are balanced and would require a 10K/600 Gardners. Model number I cant remember nor have any in stock."[/quote]
To make this more apealing to people, if you would be interested, it would make more sense to make this as accessable to more different transformer layouts other than a Gardner. You could use any 10K/600 transformer of course. I'd be very happy to have line inputs with transformers on these.
[quote author="Wonderlandaudio"]Then I purpose the inclusion of the Baxandall EQ, which puts one B101 or B105 to play. Would be more interesting not only soundwise but buiding it.[/quote]
Please elaborate on a Baxandall EQ. Did a search and read a bit about it, but would like to hear something in layman's terms if possible.
Cheers,
T
Wonderlandaudio
Well-known member
Things as I see them right now are as follow:
- Let´s take a decision on the eq. No eq, Baxandall fixed frecuencies, Baxandall stepped frecuencies, full eq.
- This takes to choose which inverting amp to use for the EQ: B101 or B105.
- Please who´s going to order the 1166´s from Carnhill? or it´s just everyone finding his own source?
- Redrawing the boards: Tekay and I ( mostly T.K. ) have redrawn all the schematics. Anyone to make the boards?
- Getting the germanium transistors. Again: Bulk buy or everyone his own ones?
As an advance:
Electromechanical parts needed:
- 4 pole 10 pos rotary switch. Sensitivity switch.
- 50K or 47K Lin pot and 10K Lin pot for the Baxandall.
- 50K or 47K for the mid eq.
- 2 pole 6 pos for bass switchable frecs.
- 2 pole 6 pos for mid sitchable frecs.
- 2 pole 6 pos for treble switchable frecs.
Transformers:
- Gardners MU7529, 7525 or 7524 mic in.
- Marinair LO1166, LI1166 or LI1167 output.
- Your choice for line in ( in case you need it ).
- Inductors:
Cards:
- B100. Input Amp
- B104. Output Amp
- B101 or B105 ( for the Baxandall EQ )
- B101 or B105 ( for the Mid EQ ).
Transistors needed:
- B100: Acc to schematic: AC107, NKT216 or AC107. In my cards: OC44, NKT 216.
- B104: BC109c, NKT216.
- B105: BC107a, BC109c.
- B101: NKT216 x2, ACY21.
- Outside cards: OC36, NKT216, BC107c ( The last 2 only if eq is added ).
- Let´s take a decision on the eq. No eq, Baxandall fixed frecuencies, Baxandall stepped frecuencies, full eq.
- This takes to choose which inverting amp to use for the EQ: B101 or B105.
- Please who´s going to order the 1166´s from Carnhill? or it´s just everyone finding his own source?
- Redrawing the boards: Tekay and I ( mostly T.K. ) have redrawn all the schematics. Anyone to make the boards?
- Getting the germanium transistors. Again: Bulk buy or everyone his own ones?
As an advance:
Electromechanical parts needed:
- 4 pole 10 pos rotary switch. Sensitivity switch.
- 50K or 47K Lin pot and 10K Lin pot for the Baxandall.
- 50K or 47K for the mid eq.
- 2 pole 6 pos for bass switchable frecs.
- 2 pole 6 pos for mid sitchable frecs.
- 2 pole 6 pos for treble switchable frecs.
Transformers:
- Gardners MU7529, 7525 or 7524 mic in.
- Marinair LO1166, LI1166 or LI1167 output.
- Your choice for line in ( in case you need it ).
- Inductors:
Cards:
- B100. Input Amp
- B104. Output Amp
- B101 or B105 ( for the Baxandall EQ )
- B101 or B105 ( for the Mid EQ ).
Transistors needed:
- B100: Acc to schematic: AC107, NKT216 or AC107. In my cards: OC44, NKT 216.
- B104: BC109c, NKT216.
- B105: BC107a, BC109c.
- B101: NKT216 x2, ACY21.
- Outside cards: OC36, NKT216, BC107c ( The last 2 only if eq is added ).
