I'll need to figure something out soon. I have the Lo Z on the way already
Thanks for the heads up.
I will simply leave both the low and hi Z modules running all the time, the quiescent current is not terrible. < 70ma if I recall correctly.
Thank you, Russ.
Thanks all for your help.
Looks like the single female header is the way to go. I like Mark Levinson No. 25 headphone amp's implementation - basically a solderable single female header but I don't know if the parts are still available.
Hi Russ:
Will you be posting the final schematic and BOM of the Lo Z soon? Looks like I will be one of the early beta testers of the Lo Z. I'll need some guidance to find a good balance between noise and gain. I have the Lyra Clavis DC mounted now which is rated .25mv output but my balanced tube line stage has plenty of gain and current (it employs a circlotron output buffer). I seldom go beyond 9 o'clock with the volume pot when listening to the Buffalo/Ivy combo.
Any suggestons?
Looks like the single female header is the way to go. I like Mark Levinson No. 25 headphone amp's implementation - basically a solderable single female header but I don't know if the parts are still available.
Hi Russ:
Will you be posting the final schematic and BOM of the Lo Z soon? Looks like I will be one of the early beta testers of the Lo Z. I'll need some guidance to find a good balance between noise and gain. I have the Lyra Clavis DC mounted now which is rated .25mv output but my balanced tube line stage has plenty of gain and current (it employs a circlotron output buffer). I seldom go beyond 9 o'clock with the volume pot when listening to the Buffalo/Ivy combo.
Any suggestons?
Hi Russ:
I received my LO Z complete kit last week. Thanks!
I will be using low output MC cartridges ranging from .25 mv to .4 mv output. Now that I am ready to assemble, I hope you can help me with a few questions I have based on reading the thread on DIYAUDIO:
1. Should I short out R18 and R19 in order to minimize noise? Shorting out R18 and R19 also means the cartridge will be seeing 0R load – is there a penalty to the sound quality by doing so?
2. What would be the overall gain of the circuit if I short our R18 and R19 and keep the H network resistors of IC1 and IC2 intact?
3. Do I understand correctly that C3 and C4 provide the capacitance loading for the cartridge and therefore their values should be changed to reflect the cartridge manufacture’s recommendation (22pf capacitors are included in the kit)?
4. Are IC3.1, IC3.2 and their surrounding circuitry added as rumble filter?
Thanks!
I received my LO Z complete kit last week. Thanks!
I will be using low output MC cartridges ranging from .25 mv to .4 mv output. Now that I am ready to assemble, I hope you can help me with a few questions I have based on reading the thread on DIYAUDIO:
1. Should I short out R18 and R19 in order to minimize noise? Shorting out R18 and R19 also means the cartridge will be seeing 0R load – is there a penalty to the sound quality by doing so?
2. What would be the overall gain of the circuit if I short our R18 and R19 and keep the H network resistors of IC1 and IC2 intact?
3. Do I understand correctly that C3 and C4 provide the capacitance loading for the cartridge and therefore their values should be changed to reflect the cartridge manufacture’s recommendation (22pf capacitors are included in the kit)?
4. Are IC3.1, IC3.2 and their surrounding circuitry added as rumble filter?
Thanks!
1) I would try it first with them shorted, there should be no penalty with a MC cartridge.
2) It will increase gain, but not too significantly.
3) Correct. I found I could usually just omit them.
4) They are actually a servo to keep common mode around GND.
Cheers!
Russ
2) It will increase gain, but not too significantly.
3) Correct. I found I could usually just omit them.
4) They are actually a servo to keep common mode around GND.
Cheers!
Russ
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Thanks Russ!
For the servo, what's the cutoff frequency afforded by the parts included in the standard kit? What values should I use to maintain flat response to 20 Hz while cutting off rumbles caused by slightly warpped records?
Nevermind.. I spoke to soon, the servo only acts on the common mode. So there is no chance to use it as a rumble filter. It basically just tries to keep the final output centered around GND.
I've got it all going and I am amazed.
Excellent!
I hope you are enjoying it.
Brian does do a fantastic job with the kits.
With them available, I'm looking at either the kit or boards only for the Low-Z Retro. Are updated schematics & BOM available for the Low-Z version... I'd like to compare the parts needed against my stock to determine whether the kit or the raw boards make more sense for me.
TIA!
Greg in Mississippi
TIA!
Greg in Mississippi
Can all parts be found at mouser? This board seems very interesting!
Yes, for the most part. Consult the Parts List on our site, which lists the vendor and aprt numbers I used. Anything not from Mouser can be substituted with parts that are available there.
Brian,
Thanks for putting the Low-Z BOM & schematic up on the the Retro Page.
RobFreak, I did a quick glance at the BOM & priced the expensive items and unless you have a LOT of the parts sitting around and/or want to go extreme upscale, buying the kit is about as economical as ordering the parts yourself AND the OpAmps come pre-mounted. I don't mind soldering those packages, but there is a time savings and the cost extra (if any) is minimal).
Me, I'm ordering the kit version.
Greg in Mississippi
Thanks for putting the Low-Z BOM & schematic up on the the Retro Page.
RobFreak, I did a quick glance at the BOM & priced the expensive items and unless you have a LOT of the parts sitting around and/or want to go extreme upscale, buying the kit is about as economical as ordering the parts yourself AND the OpAmps come pre-mounted. I don't mind soldering those packages, but there is a time savings and the cost extra (if any) is minimal).
Me, I'm ordering the kit version.
Greg in Mississippi
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