Build Thread:PQD2

[miszt]

hmm well, I was getting only 0.5V at the +/- of the diode bridge coming from the 9V AC, so I switched it out wondering if it might be faulty, but now I'm only getting 0.1V; wrong type of diode bridge perhaps? I thought the only difference between when was the amount of current they could handle...

0.0V @ 6.5V pad, unsurprisingly if nothing is making it thru the bridge

Set your meter to read DC after the bridge (the bridge "turns AC into DC"), and for reference, check the VAC on the heater input before the bridge.

Gustav

did that already, 0.1V DC at the +/- pins of the diode bridge, the AC going in is 10V

just reading up on the LM317, and finding conflicting information, I ordered an LM317T, but I have been sent a LM317MT, which seems to be limited to 500mA out, rather than 1.5A+ on the LM317 and LM317T - could that be it? although I cant see why it would limited the voltage on the output of the diode bridge...

 

[Gustav]

did that already, 0.1V DC at the +/- pins of the diode bridge, the AC going in is 10V

just reading up on the LM317, and finding conflicting information, I ordered an LM317T, but I have been sent a LM317MT, which seems to be limited to 500mA out, rather than 1.5A+ on the LM317 and LM317T - could that be it? although I cant see why it would limited the voltage on the output of the diode bridge...

Remove regulator, check solder work, check orientation of bridge, check AC on input pins of bridge if it checks out, check DC on output pins of bridge, then replace removed regulator with suitable regulator.

Gustav

 

[miszt]

did that already, 0.1V DC at the +/- pins of the diode bridge, the AC going in is 10V

just reading up on the LM317, and finding conflicting information, I ordered an LM317T, but I have been sent a LM317MT, which seems to be limited to 500mA out, rather than 1.5A+ on the LM317 and LM317T - could that be it? although I cant see why it would limited the voltage on the output of the diode bridge...

Remove regulator, check solder work, check orientation of bridge, check AC on input pins of bridge if it checks out, check DC on output pins of bridge, then replace removed regulator with suitable regulator.

Gustav

done all that, managed to find an LM317T, put that in instead ... now the fuse has blown lol its a slow blow 500mA, but having read up on the difference between the T and MT, it seems I should be using a fuse >1.5A?

edit: triple checked everything and put a 3A fuse in, all working nicely, voltage a little low now (179V), but easily sorted

 

[miszt]

what type of 3pin connector is used to connect the filter and gain boards? I've tried 4 different types so far, none of them fit lol; I don't want to solder the wires on at the moment, as I'm sure i'll end up faffing about with one of the boards once I finally "finish"

 

[Gustav]

what type of 3pin connector is used to connect the filter and gain boards? I've tried 4 different types so far, none of them fit lol; I don't want to solder the wires on at the moment, as I'm sure i'll end up faffing about with one of the boards once I finally "finish"

I never used a connector there - just dropped the random connector footprint on the PCB for a spaced 3 way and wired it.

You should measure the pin spacing if you want to find a suitable connector.

You sure weren't kidding when you said you had a lot of question...

Gustav

 

[miszt]

what type of 3pin connector is used to connect the filter and gain boards? I've tried 4 different types so far, none of them fit lol; I don't want to solder the wires on at the moment, as I'm sure i'll end up faffing about with one of the boards once I finally "finish"

I never used a connector there - just dropped the random connector footprint on the PCB for a spaced 3 way and wired it.

You should measure the pin spacing if you want to find a suitable connector.

You sure weren't kidding when you said you had a lot of question...

Gustav

I measured them already, 3mm, unfortunetly putting "3mm pitch header" into search doesn't bring me much joy :/ ...so there must be a name for this particular type of socket, if you can remember/check the original file, that would be awesome (the tube sockets I have are extremely stiff, and i know that when it comes to replacing the tubes, i wont be able to do it safely without removing the board, so I'm putting headers on all the connection points)


I have way more questions than I have posted up, I've only posted the ones I couldn't find an answer to and figured others might find the answers useful


ps. apart from the headers and 1 missing capacitor, i'm finished! will post pics soon, apart from lots of questions and the tedium of matching components, this was surprisingly easy to build! cant wait to switch it on after years of using the UAD2 versions ...long as it works haha but I've been careful to triple check everything before soldering

thanks for being patient lol enjoyed building it tho, cant wait to get stuck into the other boards!

 

[miszt]

...also, what type of caps should I have for the 1uF and 2.2uF on the filter baord? I've bought several sets now, different voltages, but all of them huge, the wires wont even fit in the hole, even if I could fit them at a strange angle..

 

[Gustav]

...also, what type of caps should I have for the 1uF and 2.2uF on the filter baord? I've bought several sets now, different voltages, but all of them huge, the wires wont even fit in the hole, even if I could fit them at a strange angle..

1. Please gather up your remaining, basic questions about gathering parts and completing the assembly of the unit in a single post.

2. Please do this with the goal of building this unit as its laid out, rather than expanding your issues by trying to build a finely tuned, modded version of it.

Gustav

 

[miszt]

I have not "modded" the unit at all, I am keeping the components within 1% tolerance because I am a professional engineer and I want to use this unit in my work, if I want to put in the extra work to do that, well that's up to me, whats the problem?

I have only 2 questions:

1. what is the connector type, where you placed a "random" connector

2. what specific type of 1uF and 2.2uF fit the pads on the filter board?


i'm not going to apologize for being a noob with questions; don't really understand why you are being difficult about it; it would have been quicker just to answer the questions than post that impatient and unhelpful post (not for the first time either).

 

[Majestic12]

Every 2,2uF and 1 uF capacitor with 5mm lead space will fit the pcb.
It is very easy to find something suitable with nearly all electronic distributors.
WIMA brand capacitors have a wide range of different sizes and values.
For example:

http://de.farnell.com/kemet/rsbcc4220z310k/folienkondensator-pet-2-2uf-50v/dp/2496060?MER=i-9b10-00002068


Gustav maybe is a bit fed up because you are new to DIY things and want to make so much "perfect" right from the start without having enough basic knowledge about parts, electronics etc yet..
Many questions about your desired part toleraces and so on aren't so easy to answer.
One thing about DIY is that you also gather this knowledge with every project you make. But you have to accept that you can't make a masterpiece as an apprentice. And even a master makes mistakes and doesn't know everything

I could simply open a new can of worms by telling you that the magnetic coupling between the inductors on your filter pcb will probably change the total inductance and filter response far more than your 1% tolerance parts, which is probably something you did not take into account yet and probably didn't know at all.

Neither did I until I made a LC filter board on my own a few weeks ago....and I have some years of experience now.

 

[miszt]

Every 2,2uF and 1 uF capacitor with 5mm lead space will fit the pcb.
It is very easy to find something suitable with nearly all electronic distributors.
WIMA brand capacitors have a wide range of different sizes and values.
For example:

http://de.farnell.com/kemet/rsbcc4220z310k/folienkondensator-pet-2-2uf-50v/dp/2496060?MER=i-9b10-00002068


Gustav maybe is a bit fed up because you are new to DIY things and want to make so much "perfect" right from the start without having enough basic knowledge about parts, electronics etc yet..
Many questions about your desired part toleraces and so on aren't so easy to answer.
One thing about DIY is that you also gather this knowledge with every project you make. But you have to accept that you can't make a masterpiece as an apprentice. And even a master makes mistakes and doesn't know everything

I could simply open a new can of worms by telling you that the magnetic coupling between the inductors on your filter pcb will probably change the total inductance and filter response far more than your 1% tolerance parts, which is probably something you did not take into account yet and probably didn't know at all.

Neither did I until I made a LC filter board on my own a few weeks ago....and I have some years of experience now.

no one learns without asking questions, that is what forums are all about, it would be better not to reply at all, than be unhelpful, impatient and deliberately difficult

I did actually already come across a discussion about the inductors, and I'm now using a pair of don-audio, matched @ 1%, and each will be in a little metal enclosure, the way they are on the original pultec


sure I cant expect perfection first time around, but I do not see the point in doing anything without at least having a goal in mind

 

[Majestic12]

Miszt, I'm sure that Gustav had no intention to be unhelpful or rude to you. He's a very fine guy.  And he as already helped you a lot

Your capacitor size question is something very easy to answer and I'm sure you would have found out on your own by looking a bit around.

Just go on with your built and try to get it up and running. I'm sure it will work and sound fine and you'll surely want to make more things in the future which also will get better and better.

 

[Gustav]

i'm not going to apologize for being a noob with questions; don't really understand why you are being difficult about it

Theres nothing wrong with being a "n00b" or asking "n00b" questions. What you are doing now is using a trouble shooting thread (and a separately created thread on modding and tubes) as a train-of-thought live chat to bridge the gap between your ability and your ambition.

Your ambition is to be to build a finely tuned, modded version of this without even knowing how resistors and capacitors affect the filter, or how to find  5mm pitch 2u2F cap.

Theres nothing wrong with taking on a project without knowing those things. Lots of people who have successfully built a unit have no clue - They just dont widen the gap between their ability and ambition more than necessary, which means they can focus on managing the BOM without making a separate post for each BOM item.

In order for me to help you further, I simply ask you to patiently gather up your questions into a forum-friendly post, rather than use this as a chatroom, and adjust your ambition to something realistic - getting a working unit running.

Saying I am being unhelpful seems incredibly rude to me. I have spent 4 forum pages trying to help you, one part at a time, and rather than spend another 4, 8 or 12 more pages, I am making a simple request, which could also help you regain some focus.

Gustav

 

[miszt]

Perhaps I overstated my noob level, I know how a capacitor filters a signal, but that doesn't mean I can tell you exactly how every bit of this circuit is working or how much of a difference it makes using 100nF rather than 101nF - which is why I have asked (and didn't get a reply)

Gustav I appreciate your help, but you have infact refused to answer my questions a few times, until I've repeated them 3-4 times; the last 2 questions are the latest example (note that you still haven't answered lol you are just whinging because I'm not using the format you prefer - I'm sorry but the way I work is to do things in stages and make sure its right before moving on, I cannot store up lots of different problems and then come back to them; this is a trait of ADHD which I have to deal with every day)

My questions are troubleshooting, for eg couldn't read labels on pcb/schematic, couldn't find a suitable connector for the "random" one used on the pcb, couldn't work out the drop resistor value because i coupdnt find a definitive current consumption figure (you could have told me when I posted up my calculations)

Perhaps it is a language issue and I am misinterpreting things, but if I ask the same question 3-4 times and dont get an answer...well, what else am I supposed to think? So far I have been assuming that it wasn't intentional and tried to be equally patient

 

[Gustav]

What I am trying to say is, its obvious you need to have a goal, but that goal has to be realistic as in "get a working EQ going".

I am asking you to adjust that ambition to better suit your ability, and I am asking you to adjust your method, so theres not a separate post from you for every part mentioned in the BOM mixed with ambitions of fine tuning and modding the unit.

For example.

I know how a capacitor filters a signal

If this is true, then it makes no sense to ask how much a cap value will change the amplitude and frequency of a setting.

if 5% difference means i could have a 3-6db+ difference over a very wide freq range  Left/Right, then that would definitely not be good lol

First of all, switching the cap changes the frequency, and if you know how a filter works, its very simply to take the 2,2uF value for 20Hz, then deduce the impedance from that. When you have that, you can check how far the frequency strays with a change in capacitance.

..so my answer

You can order a bag of each value and sort them to 1%, or just use 5% rated capacitors

...is a combination of "If you have to ask", "Dont worry about it" and "It will be fine", and it seems like you won't accept that. It should be obvious from my answer I find 5% to be sufficient, so wether you need to match the more closely is a value judgement.

I sometimes find the need to match them to 1%, but thats based on my own experience, and my own value judgement. I also go back and tweak needed values after shooting some curves if I am building something like that, since the goal ultimately refers to the match of the equalisation curves, not the capacitor or inductor values.

I ask the same question 3-4 times and dont get an answer..

Some of the answers you get are, "wire it up, and dont worry about the connector", and "Try a resistor in the range suggested in the BOM", but those answers do not seem to be acceptable to you, so you ask again and pile on more questions.

If the working solution suggested is not good enough,  it means you will have to work it out for yourself rather than ask 3 more times. 

note that you still haven't answered lol you are just whinging because I'm not using the format you prefer

So rude....

I suggested a way forward that would help me be able to help you better, and I gave clear reasons for making that suggestion. I do feel a sense of duty with regards to helping people move forward with the projects, so I did this rather than stop replying to you.

It seems like your answer can be boiled down to "stop whinging, and just answer my question". I can only see that as a complete devaluation of my time and effort.

----

Search Mouser for "wima 5mm", click "capacitors" on the list that appears, check "5mm" in the lead spacing box, check 2.2uF in the capacitance box. Voltage rating is not an issue for the filter caps.

Hope you figure out the rest.

Gustav

 

[miszt]

..I am asking you to adjust your method,

I cant expect everyone to understand the complexities of ADHD, but asking me to adjust my method is like asking a blind person to try opening their eyes wider.

if you don't have time to check the original PCB file and see what connector you used, then just say so...really no need to drag it out into all this unpleasantness; sorry if you feel I am being rude, but I don't expect someone to spend so much time avoiding answering a simple question

 

[dribro]

3 pin connector? that's easy. I used the cheapest ones possible.

http://www.ebay.com/itm/20PCS-3-Pin-Screw-Terminal-Block-Connector-5-0mm-Pitch-301-3P-301-3P-3pin-/291497781534?hash=item43de9f291e:g:4NsAAOSw3xJVXLZE

you'll have to bend the legs a little

 

[CiaoPatsy]

Hey Gustav, just getting mine up and going - running into an issue.

I have NOS ecc83 tubes in. They power up fine when unit is turned on but slowly start to become dimmer until they seem to completely turn off.  Doesn't matter what value drop resistor I use (from the ones you recomend in the BOM) they still ultimately loose their glow.  Once they start dimming the voltage at the drop resistor slowly goes up and up to 350ish. When they are both on before they start dimming I get a reading of 220dc.

I have the Don Audio transformer for the 2 channels of G Pultecs, that I read could be used for this project.

When I put just one of either tube in, it stays on fine. I've tried it with each tube and they are both lighting up and staying on when just one tube is inserted. Either socket works the same with either tube. They stay on and drop resistor voltage is consistent.

I'm getting 6v on the 6.3v measure point.

Also, when I powered on the first time I had a short and the fuse blew. I found it was shorting  to ground along the positive side of 4700uf cap to the input on the regulator and to a pin on the rectifier. Probed around and found a bad solder. Could I have damaged something and maybe enough current isnt being supplied?

This is my first build with any tubes in it, so thank you for bearing with me!

Looking forward to get this running.

 

[Gustav]

Hey Gustav, just getting mine up and going - running into an issue.

I have NOS ecc83 tubes in. They power up fine when unit is turned on but slowly start to become dimmer until they seem to completely turn off.  Doesn't matter what value drop resistor I use (from the ones you recomend in the BOM) they still ultimately loose their glow.  Once they start dimming the voltage at the drop resistor slowly goes up and up to 350ish. When they are both on before they start dimming I get a reading of 220dc.

I have the Don Audio transformer for the 2 channels of G Pultecs, that I read could be used for this project.

When I put just one of either tube in, it stays on fine. I've tried it with each tube and they are both lighting up and staying on when just one tube is inserted. Either socket works the same with either tube. They stay on and drop resistor voltage is consistent.

I'm getting 6v on the 6.3v measure point.

Also, when I powered on the first time I had a short to ground from the positive side of 4700uf cap to input on the regulator and the a pin on the rectifier. Probed around and found a bad solder. Could I have damaged something and maybe enough current isnt being supplied?

This is my first build with any tubes in it, so thank you for bearing with me!

Looking forward to get this running.

Hi Patsy.

You mention you have 6.3V on the heater, but your symptoms are coherent with the heater supply regulator getting too hot after a bit of action and going into protection mode, resulting in loss of heater supply. When only one tubes is in, you are drawing less current through the regulator and generating less heat.

If the heater supply is lost, the tubes stop drawing current, and the high voltage will no longer be influenced by any drop resistor value. (ohms law states that V = I x R, if your heater supply is lost, I = 0, so V = 0 no matter which value you put for R).

Alternatively, you may not have sufficient current available on your heater supply.

If your regulator is shutting down, fix with heat sink (Its common to use a pad and mount the regulator to the case for heat dispersion on this project if are regulating from 12V).

If you have insufficient current, use different trafo.

And just to mention it (I assume replacing a part is the result of thorough research, but just to make sure its been mentioned). You are sure that you can replace the ECC88 for ECC83? From my limited knowledge about tubes, I would say no, even though the pinout should make it "work", but not "really work". I also dont know if there are discrepancies in heater, current draw.

Gustav

 

[bernbrue]

You need ECC88 for this, not ECC83. They are not compatible.
Bernd