DIY Simple Active Preamp
- Thread starter HypnoToad
- Start date
audiozaz
rtfm!? - tl;dr
I was eyeing the OPA2134 over at Digikey earlier.
I know I have something in a box somewhere that's supposed to be quite good too, but I forgot what exactly.az
Renron
Active Member
Hey Y'all,
Slightly OT but, has anyone (Looks to Hypno) tried the SSP before the Pass B1 or DCB1? I know it sounds kinda silly to boost then attenuate, but I was thinking........:scratch2:
Ron
Thanks to Sachin for answering all my emails.
I think he would be a nice guy to know.
Slightly OT but, has anyone (Looks to Hypno) tried the SSP before the Pass B1 or DCB1? I know it sounds kinda silly to boost then attenuate, but I was thinking........:scratch2:
Ron
Thanks to Sachin for answering all my emails.
I think he would be a nice guy to know.
sachu888
Spare the tigers, kill me
Hi Ron,
Omishra did this,there are few Indian members are using same combination.Few pics
We have done A/B comparison with/without SSP.B1 sounded always good with SSP Few pics B1 with SSP
There are members who prefers standalone SSP over B1.I know its hard to digest for Loyal Nelson Pass Fans(I am one of them)but this is the truth.
Regards,
Sachin
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Have done this. In feedback of SSP I used feedback 10kΩ in place of 8.2KΩ. So gain is 2. On B1, please note the two 10KΩ resistances below PASS LABS letters on PCB near L1 R1 labels. Before volume control those above mentioned 10KΩ inline resistance reduced max output to half. Thus extra gain is ignored. This combination did not affect negative way and AD823 maintained details as ever. It benefited as all sources can see preamp input impedance 1MΩ which is value of resistance already shunted from backside between W and CCW pads on SSP PCB. Earlier that was 13KΩ as of LSA has. This improved low end in my system.
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Renron
Active Member
Thank you Omishra and Sachin,
I gotta tell you that this forum is so easy to work with, you people are great!
I'm used to the "other" Diy_____ forum, I've learned a lot there but you don't ask questions unless you've thought about what / how your going to ask first!
There are a lot of names I recognize that bounce back and forth also.
Omishra,
You have built almost exactly what I want to build. I'm sure it sounds wonderful. Sachin sort of told me (very politely) I should incorporated the SSP into a DCB1 build, that's why I asked. I should have listened to him and just bought the SSP at the same time I bought the other boards. I regret not doing that now.
Omishra, Do I understand correctly that your SSP is a 0 gain unit?
Is that a CNC board on the right side of your enclosure? Cool!:thmbsp:
What value pot is on your LSA? 100K?
What are your secondary outputs on your Rcore? 50w?
Do you have a build thread for your CNC/SSP/LSA/OPS/B1 build?
That's a mouthful.
Thanks,
Ron
I gotta tell you that this forum is so easy to work with, you people are great!
I'm used to the "other" Diy_____ forum, I've learned a lot there but you don't ask questions unless you've thought about what / how your going to ask first!
There are a lot of names I recognize that bounce back and forth also.
Omishra,
You have built almost exactly what I want to build. I'm sure it sounds wonderful. Sachin sort of told me (very politely) I should incorporated the SSP into a DCB1 build, that's why I asked. I should have listened to him and just bought the SSP at the same time I bought the other boards. I regret not doing that now.
Omishra, Do I understand correctly that your SSP is a 0 gain unit?
Is that a CNC board on the right side of your enclosure? Cool!:thmbsp:
What value pot is on your LSA? 100K?
What are your secondary outputs on your Rcore? 50w?
Do you have a build thread for your CNC/SSP/LSA/OPS/B1 build?
That's a mouthful.
Thanks,
Ron
sachu888
Spare the tigers, kill me
Thank you Omishra and Sachin,
I gotta tell you that this forum is so easy to work with, you people are great!
I'm used to the "other" Diy_____ forum, I've learned a lot there but you don't ask questions unless you've thought about what / how your going to ask first!
There are a lot of names I recognize that bounce back and forth also.
Omishra,
You have built almost exactly what I want to build. I'm sure it sounds wonderful. Sachin sort of told me (very politely) I should incorporated the SSP into a DCB1 build, that's why I asked. I should have listened to him and just bought the SSP at the same time I bought the other boards. I regret not doing that now.
Omishra, Do I understand correctly that your SSP is a 0 gain unit?
Is that a CNC board on the right side of your enclosure? Cool!:thmbsp:
What value pot is on your LSA? 100K?
What are your secondary outputs on your Rcore? 50w?
Do you have a build thread for your CNC/SSP/LSA/OPS/B1 build?
That's a mouthful.
Thanks,
Ron
Hi Ron,
here is the build thread http://www.hifivision.com/diy/21036-pass-b1.html
Regards,
Sachin
I actually decided to build the SSP because the B1 was too clinical IMO.
Here's the SSP being fed by the HTMCPS, notice you don't need the DC blocking caps on the HTMCPS when you do this.
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Renron
Active Member
Sachin,
Thank you for mailing off the boards. I should of had you include a SSP in the lot.
You were right, again. I'll PM you later when you won't be so mad at me.....
Thank you so much for the link to HiFiVision above. That is a long thread, I'm on page 55 and it's getting good. I did not realize the amount of work you and Omishra have done for others with the GBs. Holy smokes! Board designs too! You guys are Fantastic.
Ron
Thank you for mailing off the boards. I should of had you include a SSP in the lot.
You were right, again. I'll PM you later when you won't be so mad at me.....
Thank you so much for the link to HiFiVision above. That is a long thread, I'm on page 55 and it's getting good. I did not realize the amount of work you and Omishra have done for others with the GBs. Holy smokes! Board designs too! You guys are Fantastic.
Ron
Thanks Ron, that is our madness for this hobby.
My SSP is gain 2 which is minimum with 10KΩ as feedback in place of 8.2KΩ.
At extreme right side is CNC phono stage separated with Iron mesh.
:yes:
and my r-core transformer is 22-0-22V, 30VA. Still it remains cool. But for only this application I would suggest 18-0-18, 30VA
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Renron
Active Member
Omishra,
I meant the gain on your (personal) SSP, the one installed in your enclosure.
I thought I read that you installed resistors in the volume pads to drop the gain back to 0.
Too many pages to read and remember all details.........getting old.
Anybody in the "States" have an extra SSP board to sell? PM me please.
Ron
I meant the gain on your (personal) SSP, the one installed in your enclosure.
I thought I read that you installed resistors in the volume pads to drop the gain back to 0.
Too many pages to read and remember all details.........getting old.
Anybody in the "States" have an extra SSP board to sell? PM me please.
Ron
Kappaholic
Active Member
So... You guys still recommend LDR(I have a board, needing to build) over the ALPS?
I will try to build a box with SSP & CNC + HTMCPS.
I will try to build a box with SSP & CNC + HTMCPS.
Pic of my SSP build
This might look familiar. The 25K pots are attatched via hot glue. The LED is under one of the pots- I have to peek to see if it's on. The OPA2134 is presently installed, though I have others to try. I'll probably build the power supply and I may try adapting an optivol LDR volume control to the pre. If that isn't workable I have the Lightspeed board from Sachin,though I'd need the matched LDR's. Then I'll figure out something for a presentable case. I'm feeding my Bugle phono pre through this with very nice results.
This might look familiar. The 25K pots are attatched via hot glue. The LED is under one of the pots- I have to peek to see if it's on. The OPA2134 is presently installed, though I have others to try. I'll probably build the power supply and I may try adapting an optivol LDR volume control to the pre. If that isn't workable I have the Lightspeed board from Sachin,though I'd need the matched LDR's. Then I'll figure out something for a presentable case. I'm feeding my Bugle phono pre through this with very nice results.
