24 hour wire is very loooooong one
Well, it had to go to the M2. Well, there may have been something closer, but I figured main ground of M2 would be a good one. It worked anywho. Works just great without 24 hr wire now that it has a chassis!
24 hr wire w/ alligator clip is good tool for rooting out various hum problems and experimenting with grounds, and it served well for pizza platter version of Iron Pre.
Russellc
first listen - relearning "patience grasshopper"
Tunes are outstanding. I have not heard my phone sound so good, sparrow though it may be. First thing that strikes me is the oodles of bass on simple familiar music - vocals plus a couple of instruments. Amplifier, speakers are the same as before in TV setup (previous equipment - Pioneer SC-97, same files). Difference is less stark on complex orchestral music. Thanks ZM, 6L6, everyone who helped. No problem with gains. No hum that I can hear.
Not final yet. It is in case, and only 2 inputs are wired up. And board is not secure yet; on standoffs. The relay selector don't always work. If it is correct at power on, sometimes it is active. I couldn't change inputs. After a while of twiddling, it may be that the Lorlin CK1030 selector just needed to move around a bit. No selector / relay issues now. A different kind of patience, a different kind of break-in ; I hope thats all it was. Also by accident, I discovered the selector limit switch. At first, I couldn't figure out how the selector knew that I had only 2 inputs wired.
I realize it is late to ask this. But for 2016 board, what is the recommended transformer rating? I am using 2 18v secondaries, 10VA (I thought I got this from the thread).
I attached pics of setup (no clean up, to contrast with the usual pictures posted here). +/-15V rails are good . Relay power supply is 22.4 V. The relays are 24 V Omron G5V-2 .
Again, many thanks for sharing this with us ZM. I know this is often said - but this really does make me want to listen to everything I have again. I had no idea a pre-amp could have this much of an effect.
Tunes are outstanding. I have not heard my phone sound so good, sparrow though it may be. First thing that strikes me is the oodles of bass on simple familiar music - vocals plus a couple of instruments. Amplifier, speakers are the same as before in TV setup (previous equipment - Pioneer SC-97, same files). Difference is less stark on complex orchestral music. Thanks ZM, 6L6, everyone who helped. No problem with gains. No hum that I can hear.
Not final yet. It is in case, and only 2 inputs are wired up. And board is not secure yet; on standoffs. The relay selector don't always work. If it is correct at power on, sometimes it is active. I couldn't change inputs. After a while of twiddling, it may be that the Lorlin CK1030 selector just needed to move around a bit. No selector / relay issues now. A different kind of patience, a different kind of break-in ; I hope thats all it was. Also by accident, I discovered the selector limit switch. At first, I couldn't figure out how the selector knew that I had only 2 inputs wired.
I realize it is late to ask this. But for 2016 board, what is the recommended transformer rating? I am using 2 18v secondaries, 10VA (I thought I got this from the thread).
I attached pics of setup (no clean up, to contrast with the usual pictures posted here). +/-15V rails are good . Relay power supply is 22.4 V. The relays are 24 V Omron G5V-2 .
Again, many thanks for sharing this with us ZM. I know this is often said - but this really does make me want to listen to everything I have again. I had no idea a pre-amp could have this much of an effect.
Attachments
that xformer is working , but 20-30VA is gong to be better
I resume that present one is just enough and you'll not hear difference with bigger one (tnx to Good Gemini reg), but having enough instead is better for sleep
enjoy
edit: swap places of input selector and pot
fix pcb all way right, behind moved sellector switch
then you'll have free place to move volume pot all the way back , in-line with pcb pot pads, so having shortest possible wires
use extending shaft and coupler ; for front plate bushing use face of old pot , for extending shaft look in local metal store, for coupler you can buy piece of rubber hose (5mm ID) for gasoline, look in local automotive parts store
zip ties are good enough to secure coupler
see here : Iron Pre | Zen Mod Blog
I resume that present one is just enough and you'll not hear difference with bigger one (tnx to Good Gemini reg), but having enough instead is better for sleep
enjoy
edit: swap places of input selector and pot
fix pcb all way right, behind moved sellector switch
then you'll have free place to move volume pot all the way back , in-line with pcb pot pads, so having shortest possible wires
use extending shaft and coupler ; for front plate bushing use face of old pot , for extending shaft look in local metal store, for coupler you can buy piece of rubber hose (5mm ID) for gasoline, look in local automotive parts store
zip ties are good enough to secure coupler
see here : Iron Pre | Zen Mod Blog
Last edited:
that xformer is working , but 20-30VA is gong to be better
I resume that present one is just enough and you'll not hear difference with bigger one (tnx to Good Gemini reg), but having enough instead is better for sleep
enjoy
edit: swap places of input selector and pot
fix pcb all way right, behind moved sellector switch
then you'll have free place to move volume pot all the way back , in-line with pcb pot pads, so having shortest possible wires
use extending shaft and coupler ; for front plate bushing use face of old pot , for extending shaft look in local metal store, for coupler you can buy piece of rubber hose (5mm ID) for gasoline, look in local automotive parts store
zip ties are good enough to secure coupler
see here : Iron Pre | Zen Mod Blog
Thank you for the suggestions. Neat coupler ideas.
I'll switch selector and pot. The front face has LED holes next to the selector. But no light show. I might add power led, because I keep having to look at switch to check on, off.
Forgot to say, signal, pot wires are from a broken hdmi cable, inspired by 6L6.
I used Antek 50 VA model I used in most all my preamp builds here. More than needed, but it comes shielded and is very affordable.
Russellc
Oddity with my Iron Pre (no doubt user/builder error)
With several extension kits on the way from Parts Connexion I can complete rewire of Iron Pre. Hopefully it will include proper orientation of board. This will require a bit of rewiring and I have been waiting to fix the one oddity I have had with my build.
2 inputs used of the 5 inputs available (all 5 are active) with Iron pre, 6th position is nothing, used as mute position, and maybe it should be hooked to something? Anyway the 2 inputs on this rig (TV room) are my laptop with Audioquest Dragonfly red, and the other is a Samsung smart TV via its optical out, to an inexpensive D/A converter, rca interconnects to Iron pre.
I noticed it playing recording of jazz in live venue, which has a little audience noise in the recording that can be heard between cuts and in quiet passages.
I also have the annoying habit of watching something on TV that really does not need to be listened to so volume down, music from computer stream mentioned. Well during a commercial and a quiet passage of music playback that the background noise wasnt always on the recording,but what was playing on TV, just very quietly. Turning the volume all the way down on the inexpensive D/A converter cured that. No, optical out was not selected, regular TV speaker turned all the way down.
Second time I noticed it was a little stranger. TV not on at all. Music streamed from computer as described, but volume VERY low. Then I noticed I had left selector switch to TV but a low volume from other input was leaking in. Returned selector to the input music was plugged into, and had normal volume.
All other inputs, (even if traded around) are dead silent. Hearing the TV in background of music was sort of understandable, (even though optical out not activated, obviously some leaks through) but was surprised when the low volume appeared on the source the turned off TV was in.
Yes the wiring from board to input RCAs is a little longer than if board was in best position, but would it cause crosstalk ONLY between the 2 inputs with something actually plugged into them.
I'm figuring I have mis wired something, will find in rewire hopefully but if any ideas, please I'm all ears!
Also, if I disconnect other input to Iron Pre and play music, no leak through on any other selector positions.
Russellc
With several extension kits on the way from Parts Connexion I can complete rewire of Iron Pre. Hopefully it will include proper orientation of board. This will require a bit of rewiring and I have been waiting to fix the one oddity I have had with my build.
2 inputs used of the 5 inputs available (all 5 are active) with Iron pre, 6th position is nothing, used as mute position, and maybe it should be hooked to something? Anyway the 2 inputs on this rig (TV room) are my laptop with Audioquest Dragonfly red, and the other is a Samsung smart TV via its optical out, to an inexpensive D/A converter, rca interconnects to Iron pre.
I noticed it playing recording of jazz in live venue, which has a little audience noise in the recording that can be heard between cuts and in quiet passages.
I also have the annoying habit of watching something on TV that really does not need to be listened to so volume down, music from computer stream mentioned. Well during a commercial and a quiet passage of music playback that the background noise wasnt always on the recording,but what was playing on TV, just very quietly. Turning the volume all the way down on the inexpensive D/A converter cured that. No, optical out was not selected, regular TV speaker turned all the way down.
Second time I noticed it was a little stranger. TV not on at all. Music streamed from computer as described, but volume VERY low. Then I noticed I had left selector switch to TV but a low volume from other input was leaking in. Returned selector to the input music was plugged into, and had normal volume.
All other inputs, (even if traded around) are dead silent. Hearing the TV in background of music was sort of understandable, (even though optical out not activated, obviously some leaks through) but was surprised when the low volume appeared on the source the turned off TV was in.
Yes the wiring from board to input RCAs is a little longer than if board was in best position, but would it cause crosstalk ONLY between the 2 inputs with something actually plugged into them.
I'm figuring I have mis wired something, will find in rewire hopefully but if any ideas, please I'm all ears!
Also, if I disconnect other input to Iron Pre and play music, no leak through on any other selector positions.
Russellc
Last edited:
give me close-up of your present arrangement of preamp
I did route it that all non-selected inputs are grounded, and there is separate line on pcb for that , from central GND point to relays; sometimes is better with that ( grounding them) sometimes is better to leave them floating
that's why in last (hopefully final
) iteration of pcbs , there is jumper in that grounding line, so one can choose what to do
I did route it that all non-selected inputs are grounded, and there is separate line on pcb for that , from central GND point to relays; sometimes is better with that ( grounding them) sometimes is better to leave them floating
that's why in last (hopefully final
) iteration of pcbs , there is jumper in that grounding line, so one can choose what to doI'll get pic up directly, right now the selector and volume are on front panel, extensions on way. So for now, twisted lines to volume pot and wires from grid/board to selector.
Just thought it odd bleed through only occurs between any 2 inputs that have something connected to them. I mean the problem is easy enough to avoid, I just thought its existence was reason to suspect I had something wrong somewhere in hookup.
You would think if bleed through, it would happen with one input source used and the other inputs left open. Here it requires another source connected. And even with that source off, the other used input's signal can be heard, quietly when that source is selected. Somehow I've done something allowing use inputs to "share" the signal, albeit very quietly.
Thanks, I'm digging it out of the system and putting something else there for now, will get pics of birds nest....it will be short and stout when extensions arrive and rewire begins.
I think replacement for now will be BA3 FE I just installed I-Select in. If it doesnt do this, (never noticed it) I can at least stare at wiring for differences.
Thanks,
Russellc
Just thought it odd bleed through only occurs between any 2 inputs that have something connected to them. I mean the problem is easy enough to avoid, I just thought its existence was reason to suspect I had something wrong somewhere in hookup.
You would think if bleed through, it would happen with one input source used and the other inputs left open. Here it requires another source connected. And even with that source off, the other used input's signal can be heard, quietly when that source is selected. Somehow I've done something allowing use inputs to "share" the signal, albeit very quietly.
Thanks, I'm digging it out of the system and putting something else there for now, will get pics of birds nest....it will be short and stout when extensions arrive and rewire begins.
I think replacement for now will be BA3 FE I just installed I-Select in. If it doesnt do this, (never noticed it) I can at least stare at wiring for differences.
Thanks,
Russellc
Last edited:
![IMG_4794[1].JPG](/community/data/attachments/781/781189-412f0006b071d5e79e617743f3bf0c55.jpg)
24h rotation, silly ...... and you can't tell that I didn't told you before
reason is that you bundled all those wires together, there must be crosstalk, especially with unused inputs routed to GND (muted)
now, you have solution - either cut GND trace which is connected to relays to mute unused inputs , or rotate pcb 90deg CCW, to be oriented as I planned it to be - to have properly short wires from RCAs to input pads, so being properly separated
I prefer rotation, though, if you insist - I can see later which trace needs cutting, but be aware that I can't be sure that it will cure crosstalk 100%
looking good
to remind you - you need small heatsinks just for BD transistors, no need to put them on mosfets
......and considering that all channels are sharing same audio GND, putting NTC to chassis on just one pcb should be enough
Last edited: