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  1. joshvito

    Troubleshooting help needed.

    With leads of meter connected to each other, DC/AC voltage is 0. I thought if may be a meter problem, but the fact that it happens on both meters seems to confirm the problem.
  2. joshvito

    Troubleshooting help needed.

    I re-posted over there too.
  3. joshvito

    Troubleshooting help needed.

    I've tested this value while the preamp is powered up, with no outputs or inputs signal. It is stable at the expected 220vDC. I didn't monitor long tho. maybe 2-3 minutes.
  4. joshvito

    Troubleshooting help needed.

    I'll get some smaller output caps. I had 2.2uF in there, but accidentally melted one with my iron. Sadly, I don't have access to a scope. The only difference in my circuit from the scematic (now that pilot led is out), is a DPDT switch in between the rotarty switch and volume pot. Input grounds...
  5. joshvito

    Troubleshooting help needed.

    Here is a link to a video of what the MM does when connected to the RCA with no input connected and no output connected. Is this normal for a SE tube pre?
  6. joshvito

    Troubleshooting help needed.

    I measured the output RCA ground with multimeter attached to output ground and input ground. DC and AC voltages were 0. I also measured output RCA ground with meter attached to output ground and chassis earth. This was also 0 (actually, meter read 0.1mV). Then,I removed the LED and tested...
  7. joshvito

    Troubleshooting help needed.

    The 4.7 output caps are film caps.Thanks for the troubleshooting tips. I'll check the voltages tomorrow and report back. I added an LED in serious with a resistor on one of the AC heater wires to ground. Could that be causing an issue ? I was attempting to add a pilot light.
  8. joshvito

    Troubleshooting help needed.

    The preamp output caps are 4.7uF. I have a lot of build pics at http://imgur.com/gallery/9yhVOzz
  9. joshvito

    Troubleshooting help needed.

    I built a single ended tube preamp (the circuit is here https://wtfamps.com/sofrito-preamplifier/). The preamp seems to be working great, however, my amplifier kicked into protection mode this evening. So, I decided to check to see if there was DC on the outputs of the preamp. I hooked up my...
  10. joshvito

    New build: how to install RCA with isolation washers?

    I have some switchcraft RCA connectors (3501FRX), and I also have the manufacturer recommended isolation washers (s1028 and s1029). Does anyone know what order/how to install these so they are isolated? I can't seem to find a drawing or anything. I just don't know where to put the isolation...
  11. joshvito

    Tube Preamp input/output wiring questions

    Thank you for the explanation. Makes sense. I suppose, if I wanted to remove the resistance of the volume pot, I could put a switch in between to remove the pot from the circuit. Downside would be, more wire and the extra switch in the signal chain.
  12. joshvito

    Tube Preamp input/output wiring questions

    Yea, he didn't show his work on that write up (he does document it else where tho). But if I look up formulas for Grounded Cathode Amplifier Output Impedance, I find... Zo = Rl || Rp (plate load resistor "in parallel to" internal plate resistance) = 5k || 1.8k = 1323.53 Ohm That gives...
  13. joshvito

    Tube Preamp input/output wiring questions

    Can you tell me how you calculated the 1.8k Ohm output impedance? Sorry, I am just trying to learn as I go. I only as, as the author of the circuit mentions an Output impedance of 1200 Ohm. Which puts the ratio at12+. Thanks again, now I am off to read more about cathode followers. :)
  14. joshvito

    Tube Preamp input/output wiring questions

    Thanks. This is helpful, looks like I will keep one output instead of two from the preamp circuit. Especially, since this is my first custom build. I still want to try and incorporate a pass through if possible, so I can leave this tube preamp off and pass the signal out to another preamp.
  15. joshvito

    Tube Preamp input/output wiring questions

    Yes. I plan on using a 6V6 for the audio. Isn't the volume pot usually after the input selector switch? More specifically, I was thinking about the "pass through" related to the first question would get connected to the input of the Aux RCA (20k ohms) of my Marantz PM8005. .. and the tube...
  16. joshvito

    Tube Preamp input/output wiring questions

    I am building a tube based preamp (ptp wiring), and have 2 questions about wiring the inputs and outputs. I have planned for 3 pairs of inputs (rca) and 3 pairs of outputs (rca). The 3 inputs are planned to go to a rotary switch. The wiring I have planned from the switch is where I have...
  17. joshvito

    Record Bin From single 4 x 8 Sheet of Plywood - Plans

    The mini jig is harder to keep in place due to it's size. Also, the standard pocket hole jig will save you some time, as you can drill 2 holes per clamping. I used this model...
  18. joshvito

    Record Bin From single 4 x 8 Sheet of Plywood - Plans

    Here is the result of my inspiration from this thread. If you are interested in progress photos, I have some posted at https://imgur.com/a/mdDTeJg Now I need to go off to the local record store to fill the shelf. It will give me an excuse to build a matching one. :) Happy spinning.
  19. joshvito

    New CDP?

    Subscibed. I'm also considering adding a CD transport to my system. Let's see where this goes.
  20. joshvito

    Anyone make custom cork mats?

    At one point, on Reddit, I saw a user on /r/vinyl or /r/vintageaudio who was making custom cork matts. I'm not sure if he is still around, but he had a web store and was taking commissions.
  21. joshvito

    MC Phono Pre Noise Floor

    I ended up purchasing The Black Cube to upgrade my system. If you are interested, I posted a review/story @ http://audiokarma.org/forums/index.php?threads/review-upgrading-a-mc-phono-stage.829225/
  22. joshvito

    Review: Upgrading a MC Phono Stage

    A review of The Black Cube from Lehmann Audio in comparison to the Parasound zPhono. This article will not go into details on why one needs a phono stage in their HIFI system. It will assume the reader knows the basics of vinyl playback on modern HIFI stereo systems. Notes on the gear involved...
  23. joshvito

    MC Phono Pre Noise Floor

    I was looking at this unit also, but was turned off at the low S/N ratio of 63, it is not much better than the 58 of the Parasound zPhono. The loading options do sound nice, but is it at the cost of more noise, which is the originator of this thread? Also, where are you shopping? Seems like...
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