The Iron Pre is now listed in the diyAudio store for anyone to purchase. No codes or tricks needed.
Until the 'Build Guide / Build Thread' is created, this post will contain all current schematics and notes for the Iron Pre sold through the diyAudio store. Check back frequently to ensure you have the latest files.
Sep 14 2023 - Below is what you're waiting for! See some awesome information and help from 6L6 on the SE build. A new thread and the guide using the web interface will be posted ... soon. Post #2291
Background
Hello Happy DIYers / Greedy Boyz!
I am thrilled to announce that Zen Mod's Iron Pre essentials kits will be offered in the DIYAudio store. This is not a group buy. You can learn more about the project in the thread linked below.
https://www.diyaudio.com/community/threads/whats-wrong-with-the-kiss-boy.293169/
Highlights include matched Toshiba JFETs from Nelson Pass and high-nickel CineMag transformers. 6L6 has volunteered to post one of his incredible build guides also.
If you're a Smiths fan, you may ask, How Soon Is Now? They should be available for order before the end of the year. At this time, we have enough parts sourced for 100 SE and 50 balanced kits.
The next obvious question is, how much? Costing is not final yet, but the goal is $100 for the SE kits and $125 for the balanced kits; a tremendous bargain. We have contingencies for all the parts, and we hope that this will be a permanent addition to the store. However, for now, we can only promise what we've got. Get 'em while you can.
Click the link below to see what will be included in the kit, answer a few questions about what you might like to see in the future, and get on the list.
Note - The n-channel JFETs will be 2SK370.
Quick and Dirty Startup Process
This happens after: the boards are stuffed, the AC supply is verified and connected properly, and I/O has been connected. Nothing needs to be shorted.
4-May 2023
Edited 7-Aug 2023. All in-line photos have been removed. Please see attached files for all documentation.
5-May 2023
Updated Single-Ended BoM to correct 330R part notations in the gain stage to R28 and R29.
Attached are the Bill of Materials / Parts Lists - Note File Names for Balanced and SE
26 - May 2023
Updated SE and Balanced Bill of Materials to indicate that snubber components should not be installed.
Balanced BoM Filename - BOM_Store_Iron_Pre_Balanced_Dist_v5.pdf
SE BoM Filename - BOM_Store_Iron_Pre_SE_Dist_v5.pdf
27 - May 2023
Updated SE and Balanced Bill of Materials to correct and clearly note which diodes should be installed for input switching.
Balanced BoM Filename - BOM_Store_Iron_Pre_Balanced_Dist_v6.pdf
SE BoM Filename - BOM_Store_Iron_Pre_SE_Dist_v6.pdf
1 - June 2023
Note - No changes required. However, the packing lists some of you will receive may note LM336-5.0. That was a typo; apologies. The correct parts (as supplied and noted in the BoM) are LM336-2.5.
Removed the link to sign up indicating interest in kits. Those currently on the list will get first priority for the next round of kits. After that, they will be sold through the normal process through the store.
6 - June 2023
There are two gorgeous prototype chassis available; one designed specifically for SE, and one for Balanced. You can find some details in post #431. The depth for both chassis is 280mm. There is additional information sprinkled throughout the thread re: acceptable sizes and some potential part numbers for IECs, input / outputs etc. along with pictures of some examples. Please search first before asking chassis questions, and I'd recommend using the latest posts' information. Again, they are prototype chassis, and anything could change at any time until the design is finalized. The best source of information re: the chassis is directly from Modushop until they are sold in the diyAudio store. Timing TBD.
8 - June 2023
Added parts placement and pcb layouts for those interested.
30 - June 2023
V7 - Minor Updates to BoMs. QTY added. Ensure to check quantity per board against the quantity you need for your project. Added links to a popular online website to show examples of parts that will work for the connection between the main boards and the twister boards for input selection / LED power etc. Added generic descriptions for those that would prefer to select their own parts.
1 - July 2023
V8 - Minor Updates to BoMs. Added heatsinks for M3 if 12V relays are used.
7 - Aug 2023
I'm excited to say that more kits will be available very soon for 'round 2'. Continue checking this post (as always) and the thread overall for up to the minute updates.
In his graciousness, ZM has made some minor running changes. Changes are:
Boards that include the changes will note "2023" vs. "2021" on the silkscreen. The Twister board accompanying the 2023 boards notes V.3. Both 2021 and 2023 boards are included with 'round 2'. You cannot choose which you will receive, and you will not know which you will receive until they arrive. Do not fret if you get a kit with 2021 boards. If you need to use a particular type logic solution, there is a very easy modification previously noted in the thread, and the snubber is not necessary. The changes made were a kindness from ZM, but all 2021 boards can be made to function just like 2023 boards with a few user-tweaks described in the thread.
Note - The attachments have been packaged and note which files to choose for the respective boards. Previous attachments and in-line thumbnails / photos have been removed for clarity. The BoMs have been updated slightly for clarity.
9 - Aug 2023
There is a minor error on the silkscreen for the boards marked Iron Pre SE Zen Mod Labs 2023. The polarity notation for C11 visible when the cap is installed is incorrect. Ignore it.
13 - Aug 2023
His Mightiness created two graphics for how to wire standard pots for both SE and Balanced. Attached.
29 - Aug 2023
Minor updates to balanced BoMs. Removed reference to D15.
31 - Aug 2023
Added wiring diagram for AVC for SE. See post #2113 for context.
Until the 'Build Guide / Build Thread' is created, this post will contain all current schematics and notes for the Iron Pre sold through the diyAudio store. Check back frequently to ensure you have the latest files.
Sep 14 2023 - Below is what you're waiting for! See some awesome information and help from 6L6 on the SE build. A new thread and the guide using the web interface will be posted ... soon. Post #2291
Background
Hello Happy DIYers / Greedy Boyz!
I am thrilled to announce that Zen Mod's Iron Pre essentials kits will be offered in the DIYAudio store. This is not a group buy. You can learn more about the project in the thread linked below.
https://www.diyaudio.com/community/threads/whats-wrong-with-the-kiss-boy.293169/
Highlights include matched Toshiba JFETs from Nelson Pass and high-nickel CineMag transformers. 6L6 has volunteered to post one of his incredible build guides also.
If you're a Smiths fan, you may ask, How Soon Is Now? They should be available for order before the end of the year. At this time, we have enough parts sourced for 100 SE and 50 balanced kits.
The next obvious question is, how much? Costing is not final yet, but the goal is $100 for the SE kits and $125 for the balanced kits; a tremendous bargain. We have contingencies for all the parts, and we hope that this will be a permanent addition to the store. However, for now, we can only promise what we've got. Get 'em while you can.
Note - The n-channel JFETs will be 2SK370.
Quick and Dirty Startup Process
This happens after: the boards are stuffed, the AC supply is verified and connected properly, and I/O has been connected. Nothing needs to be shorted.
- Set V+ and V-
Adjust P1 and P2 for each board until V+ is +15V0 and V- is -15V0
GND, V+ and V- pads are clearly marked on PCBs.
Do not move forward if you cannot adjust the voltages to within 0V1 or if the voltage seems unstable.
- Null DC offset
- SE
- No jumper caps in place for JP1 or JP2
- Measure at center pin of JP1 and JP2 NOT between those two pins*
- Turn P3 / P4 respectively until voltage shows 0V +- 5mV
- Cap the jumpers for your choice of gain.
- Balanced
- No jumper caps on JP+ or JP-
- Measure at pin 1 of JP+ and JP- NOT between those two pins*
- Turn P3 / P4 respectively until voltage shows 0V +- 5mV
- Cap the jumpers.
- SE
Do not move forward if you cannot null the offsets to less than +- 5mV
3. Sing Happy Tunes
*Measure at a particular point => Measure between that point and GND.
Updates4-May 2023
Edited 7-Aug 2023. All in-line photos have been removed. Please see attached files for all documentation.
5-May 2023
Updated Single-Ended BoM to correct 330R part notations in the gain stage to R28 and R29.
Attached are the Bill of Materials / Parts Lists - Note File Names for Balanced and SE
26 - May 2023
Updated SE and Balanced Bill of Materials to indicate that snubber components should not be installed.
Balanced BoM Filename - BOM_Store_Iron_Pre_Balanced_Dist_v5.pdf
SE BoM Filename - BOM_Store_Iron_Pre_SE_Dist_v5.pdf
27 - May 2023
Updated SE and Balanced Bill of Materials to correct and clearly note which diodes should be installed for input switching.
Balanced BoM Filename - BOM_Store_Iron_Pre_Balanced_Dist_v6.pdf
SE BoM Filename - BOM_Store_Iron_Pre_SE_Dist_v6.pdf
1 - June 2023
Note - No changes required. However, the packing lists some of you will receive may note LM336-5.0. That was a typo; apologies. The correct parts (as supplied and noted in the BoM) are LM336-2.5.
Removed the link to sign up indicating interest in kits. Those currently on the list will get first priority for the next round of kits. After that, they will be sold through the normal process through the store.
6 - June 2023
There are two gorgeous prototype chassis available; one designed specifically for SE, and one for Balanced. You can find some details in post #431. The depth for both chassis is 280mm. There is additional information sprinkled throughout the thread re: acceptable sizes and some potential part numbers for IECs, input / outputs etc. along with pictures of some examples. Please search first before asking chassis questions, and I'd recommend using the latest posts' information. Again, they are prototype chassis, and anything could change at any time until the design is finalized. The best source of information re: the chassis is directly from Modushop until they are sold in the diyAudio store. Timing TBD.
8 - June 2023
Added parts placement and pcb layouts for those interested.
30 - June 2023
V7 - Minor Updates to BoMs. QTY added. Ensure to check quantity per board against the quantity you need for your project. Added links to a popular online website to show examples of parts that will work for the connection between the main boards and the twister boards for input selection / LED power etc. Added generic descriptions for those that would prefer to select their own parts.
1 - July 2023
V8 - Minor Updates to BoMs. Added heatsinks for M3 if 12V relays are used.
7 - Aug 2023
I'm excited to say that more kits will be available very soon for 'round 2'. Continue checking this post (as always) and the thread overall for up to the minute updates.
In his graciousness, ZM has made some minor running changes. Changes are:
- Updated transformer snubber circuit.
- Easier positioning / mounting of the CineMag transformers in some situations.
- Changes to allow easier use of some logic circuits for input switching.
Boards that include the changes will note "2023" vs. "2021" on the silkscreen. The Twister board accompanying the 2023 boards notes V.3. Both 2021 and 2023 boards are included with 'round 2'. You cannot choose which you will receive, and you will not know which you will receive until they arrive. Do not fret if you get a kit with 2021 boards. If you need to use a particular type logic solution, there is a very easy modification previously noted in the thread, and the snubber is not necessary. The changes made were a kindness from ZM, but all 2021 boards can be made to function just like 2023 boards with a few user-tweaks described in the thread.
Note - The attachments have been packaged and note which files to choose for the respective boards. Previous attachments and in-line thumbnails / photos have been removed for clarity. The BoMs have been updated slightly for clarity.
9 - Aug 2023
There is a minor error on the silkscreen for the boards marked Iron Pre SE Zen Mod Labs 2023. The polarity notation for C11 visible when the cap is installed is incorrect. Ignore it.
13 - Aug 2023
His Mightiness created two graphics for how to wire standard pots for both SE and Balanced. Attached.
29 - Aug 2023
Minor updates to balanced BoMs. Removed reference to D15.
31 - Aug 2023
Added wiring diagram for AVC for SE. See post #2113 for context.
Attachments
Last edited:
Just so I can stop watching the store for this, a question. Great it is making it to the store! Now, are the 100 SE and 50 balanced the units what "will make it to the store" at end of year, or these kits (100 + 50) for those who sign up, and there will be others available after the first of the year?
Russellc
Russellc
SE is 5 SE inputs, 1 or 2 SE outputs ( simple paralleling of RCA jacks on back)
Bal is 5 Bal inputs, Bal output + SE output ( SE being simple GND and positive phase taken from XLR to RCA); both outputs functional in same time
arbitrary number of any of 5 inputs can be easily arranged as SE, catch being that is done internally in preamp, not simple shorting plug on XLR
example - permanently wired with 3 SE inputs and 2 Bal inputs; though - each input easily reverted to other type
details - Bal input converted to SE in two steps : 1. shorting neg input to GND
2. placing shorting jumper (on pcb) for particular input, thus enabling SE operation of input
all that already explained somewhere in origin thread, and will be detailed again in Building Guide, by Mighty 6L6
I mean - one can really organize Bal/Se trickery in several ways ....... say mounting all XLRs at back, then for SE you need to have custom cable (RCA+XLR with neg phase shorted to GND) and placing mentioned jumper inside
what is important - it is working fully as SE to Bal and Bal to SE converter
Bal is 5 Bal inputs, Bal output + SE output ( SE being simple GND and positive phase taken from XLR to RCA); both outputs functional in same time
arbitrary number of any of 5 inputs can be easily arranged as SE, catch being that is done internally in preamp, not simple shorting plug on XLR
example - permanently wired with 3 SE inputs and 2 Bal inputs; though - each input easily reverted to other type
details - Bal input converted to SE in two steps : 1. shorting neg input to GND
2. placing shorting jumper (on pcb) for particular input, thus enabling SE operation of input
all that already explained somewhere in origin thread, and will be detailed again in Building Guide, by Mighty 6L6
I mean - one can really organize Bal/Se trickery in several ways ....... say mounting all XLRs at back, then for SE you need to have custom cable (RCA+XLR with neg phase shorted to GND) and placing mentioned jumper inside
what is important - it is working fully as SE to Bal and Bal to SE converter
none, for now ........ and nobody asked for
anyhow, for planned/projected price range**, you can't expect that
considering that you need to bring/choose your attenuator option, nothing is preventing you to pay for remote controlled package; if there is input selection function, it's certainly trivial to glue it on Iron Pre selector circuit
**for instance - SE stereo kit package you get for less money than you'll pay for pair of Cinemags, if you're buying them directly ......... so - pcb, Cinemags, JFEts, some bjts; if that is not generous and enthusiastic, dunno what is
anyhow, for planned/projected price range**, you can't expect that
considering that you need to bring/choose your attenuator option, nothing is preventing you to pay for remote controlled package; if there is input selection function, it's certainly trivial to glue it on Iron Pre selector circuit
**for instance - SE stereo kit package you get for less money than you'll pay for pair of Cinemags, if you're buying them directly ......... so - pcb, Cinemags, JFEts, some bjts; if that is not generous and enthusiastic, dunno what is
well, yes, sorta
sorta means few buts (without ifs):
- I don't want Iron Pre being vehicle for me to sell more Iron Turtles; Iron Pre is intended to be a gift and it needs to stay that; my intention was to make that as gift to our Store, and Jason and Pa and Co evidently decided price making it as direct gift for interested Greedy boyz; Kudos to them!
- buffer - 2SK2145 triples really being more ballsy than pair of TO92, and Turtle salutes that
-Turtle really deserves best possible overall arrangement, which Iron Pumpkin MoBo really is; basic logic and arrangement of IP vs. IP
is same, but big one really making life much easier - lesser wiring hassle as first thing and then all tiny bits and details as result of using one big piece of pcb containing everything (that also I learned staring at GOATS ...... I mean - PL preamps; you know well who made them)
even if I'm extremely late with proper new dedicated thread for now evidently final iteration of Iron Pumpkin, all of above lead me to decide that I'm not going to offer neither AVC nor electronic (for Iron Pumpkin) as separate articles
sorta means few buts (without ifs):
- I don't want Iron Pre being vehicle for me to sell more Iron Turtles; Iron Pre is intended to be a gift and it needs to stay that; my intention was to make that as gift to our Store, and Jason and Pa and Co evidently decided price making it as direct gift for interested Greedy boyz; Kudos to them!
- buffer - 2SK2145 triples really being more ballsy than pair of TO92, and Turtle salutes that
-Turtle really deserves best possible overall arrangement, which Iron Pumpkin MoBo really is; basic logic and arrangement of IP vs. IP
is same, but big one really making life much easier - lesser wiring hassle as first thing and then all tiny bits and details as result of using one big piece of pcb containing everything (that also I learned staring at GOATS ...... I mean - PL preamps; you know well who made them)even if I'm extremely late with proper new dedicated thread for now evidently final iteration of Iron Pumpkin, all of above lead me to decide that I'm not going to offer neither AVC nor electronic (for Iron Pumpkin) as separate articles
