Perfect. The pic of the single ended face play is perfect and answered all my concerns. Back to ordering.
Russell
I am slowly getting everything I need for my IronPre. I have decided to bite the bullit and do it properly, so I just ordered the balanced enclosure from Modushop because I know otherwise I run the risk it will become one of those never-completely-finished projects!
I decided to go with duck bill knobs for volume and input selection, and ordered those at Aliexpress. I had already bought transformers (and covers!) from Antek and all the passives either come from what have in my cupboard or were ordered from Mouser recently. Just a few things left:
Volume adjustment:
I am unsure what to do. I could use ordinary Alps pots, but have been looking at the EIZZ stepped attenuators. I understand they use carbon resistors, I think in a series configuration. Has anyone tried these? Are they worth the extra expense? Alternative suggestions would be appreciated.
Relays:
I have plenty of 12V relays that I bought from Aliexpress a few years ago. They are a muddy yellow and marked HUI KE HK19F-DC 12V-SHG. According to the attached datasheet (assuming the ones I bought were not fakes) the contact material is silver alloy.
Does anyone have any experience with these?
Input selection switch
Is there an alternative or is the Lorlin CK1060 the only one guaranteed to fit the selector pcb? I ask because I have not yet ordered it and shipping costs are higher than the price of the switch :-(
I decided to go with duck bill knobs for volume and input selection, and ordered those at Aliexpress. I had already bought transformers (and covers!) from Antek and all the passives either come from what have in my cupboard or were ordered from Mouser recently. Just a few things left:
Volume adjustment:
I am unsure what to do. I could use ordinary Alps pots, but have been looking at the EIZZ stepped attenuators. I understand they use carbon resistors, I think in a series configuration. Has anyone tried these? Are they worth the extra expense? Alternative suggestions would be appreciated.
Relays:
I have plenty of 12V relays that I bought from Aliexpress a few years ago. They are a muddy yellow and marked HUI KE HK19F-DC 12V-SHG. According to the attached datasheet (assuming the ones I bought were not fakes) the contact material is silver alloy.
Does anyone have any experience with these?
Input selection switch
Is there an alternative or is the Lorlin CK1060 the only one guaranteed to fit the selector pcb? I ask because I have not yet ordered it and shipping costs are higher than the price of the switch :-(
EIZZ - dunno, with time I'm less and less impressed with differences between cheaper and costlier switch+resistor matrix attenuators
there are small ones, made with smd metalfilms (contained inside, not soldered on blue-white rotaries) but I can't recall their brand
Huike relays - mid tier quality, use them if you have them ; worst that can happen is that you change few or all in 10 years; 12V coils - take care to put appropriate zener (16V) in relay PSU and install small heatsink on IRF510
Lorlin - if you have any appropriate, just wire pcb on it, proper DIY fashion; make-before-break is advisory
there are small ones, made with smd metalfilms (contained inside, not soldered on blue-white rotaries) but I can't recall their brand
Huike relays - mid tier quality, use them if you have them ; worst that can happen is that you change few or all in 10 years; 12V coils - take care to put appropriate zener (16V) in relay PSU and install small heatsink on IRF510
Lorlin - if you have any appropriate, just wire pcb on it, proper DIY fashion; make-before-break is advisory
Thanks.
I'll use the relays I have and I have plenty spares to replace any ones that fail.
I think I will wait with the switch until I have more to order, and order the Lorlin. May as well try to do a neat job this time 🙂
I have seen DACT with smd resistors, but they are quite expensive. A stereo EIZZ is about €45, incl, shipping (2 needed). There are some cheaper series models (blue/white switch) on Aliexpress, but not that big a price difference. I'll have to think about this some more.
What is your experience when you compare stepped attenuators to an Alps 27?
I'll use the relays I have and I have plenty spares to replace any ones that fail.
I think I will wait with the switch until I have more to order, and order the Lorlin. May as well try to do a neat job this time 🙂
I have seen DACT with smd resistors, but they are quite expensive. A stereo EIZZ is about €45, incl, shipping (2 needed). There are some cheaper series models (blue/white switch) on Aliexpress, but not that big a price difference. I'll have to think about this some more.
What is your experience when you compare stepped attenuators to an Alps 27?
The main advantage (for me) with a stepped attenuator can be better channel tracking due to matching resistors / finer tolerance.
Since you're using two, two gang pots vs. one four gang... I wouldn't give it a second thought between channels, and I doubt I could hear a difference with a tiny mismatch between phases of the same channel. However, that's only me, and I may be missing a key thing.... and mismatch is typically at its worst at higher attenuations, which I avoid.
Note - I don't think the different types of resistor composition in the stepped (if you get to choose them or are building it yourself) have an effect that I can hear.
YMMV and all that.
Can't wait to see your build... It sounds like it's going to be fantastic.
Since you're using two, two gang pots vs. one four gang... I wouldn't give it a second thought between channels, and I doubt I could hear a difference with a tiny mismatch between phases of the same channel. However, that's only me, and I may be missing a key thing.... and mismatch is typically at its worst at higher attenuations, which I avoid.
Note - I don't think the different types of resistor composition in the stepped (if you get to choose them or are building it yourself) have an effect that I can hear.
YMMV and all that.
Can't wait to see your build... It sounds like it's going to be fantastic.
Thanks. Yes, channel and phase mismatch and all that. Talk about audio nervosa!
I built a Takman based 24 position shunt for my B1 years ago (blue/white switch). And then a Dale based. They sound great but I never compared them to an Alps so that does not help me much. They were a mongrel to build, so I am not sure I want to do that again haha.
I think I will check my cupboard tomorrow. I think I have two 50k Alps stashed away, and they can't be that bad (at least they are not some realky cheap pot). Perhaps it will be worthwhile to check if the resistance at a few different positions is reasonably close and then just go for it.
Haha, I have stopped counting how much I spent on it (bloody shipping costs, grr), but it better be fantastic ;-)
I built a Takman based 24 position shunt for my B1 years ago (blue/white switch). And then a Dale based. They sound great but I never compared them to an Alps so that does not help me much. They were a mongrel to build, so I am not sure I want to do that again haha.
I think I will check my cupboard tomorrow. I think I have two 50k Alps stashed away, and they can't be that bad (at least they are not some realky cheap pot). Perhaps it will be worthwhile to check if the resistance at a few different positions is reasonably close and then just go for it.
Haha, I have stopped counting how much I spent on it (bloody shipping costs, grr), but it better be fantastic ;-)
I ordered a couple of the EIZZ a week ago. Unfortunately they take three weeks or so to arrive, so I can't give any feedback yet. I decided to try them because they are way less expensive than the similar Gold Point stepped attenuators I've used in other builds.
My simple and temporary solution to this issue is to not max the volume pots and stick my ear against the speaker. My long term solution is to do a total rebuild using an outboard PS. This will which give me room to separate the preamp boards and then run the pots with shafts moving them closer to the connectors on the board.
I won't be ready to install attenuators for weeks at least, so I will be very interested to hear your experiences with the eizz! Please post your impressions!
I am working out with Gianluca a custom rear panel and have noticed that the cutout for the power module (Schurter DD12 series) appears to be smaller (27.9 x 46.9 mm, confirmed by Gianluca) than the one suggested in the datasheet (29.8 x 49.3 mm).
CAD file:
Datasheet:
Does anyone that has already assembled the chassis noticed any problem?
A couple of millimeters may not be an issue at all and a tight fit may even be desiderable. Just curious.
CAD file:
Datasheet:
Does anyone that has already assembled the chassis noticed any problem?
A couple of millimeters may not be an issue at all and a tight fit may even be desiderable. Just curious.
The DD12 fits nicely in my built.
It was a "press fit" and it has to be inserted from the "inside" so it is the plastic frame that it inserted in the hole.
From the outside it is to possible. Then it is too large to fit.
It was a "press fit" and it has to be inserted from the "inside" so it is the plastic frame that it inserted in the hole.
From the outside it is to possible. Then it is too large to fit.
Is there an accessible Mouser cart for the s/e version saved by any chance? I've ploughed through many pages searching, but if anyone could point me to a relevant post it would be greatly appreciated. TIA.
Only a partial one:
https://www.diyaudio.com/community/...re-register-your-interest.390509/post-7375247
Not sure if it's for SE or Balanced
https://www.diyaudio.com/community/...re-register-your-interest.390509/post-7375247
Not sure if it's for SE or Balanced
If not you can build your own using Patrick’s spreadsheet. Just use the BOM import tool to upload the .xls file. It’s a little clunky, but saves a ton of typing or copy/paste.