Questions about popping noise

[psychepool]

I was interested in the composition of Orange Dual Dark, so I looked at the related circuits.
I can't find Dual Dark's official circuit, so I have to guess, but judging from the tube layout, I'm guessing that the Jim Root Terror and Dark Terror preamps are probably assigned to each channel and switched. (In other words, Rockerverb pre + Th30 pre)

In fact, the preamp circuits of these two are almost identical, with almost the only difference being the EQ.
Below is the Rockerverb pre.

rv_pre.jpg

Below is the Th30 and Dark terror pre.

th_pre.jpg

dt_pre.jpg

It is assumed that Dual Dark allocates each preamplifier circuit separately and switches it as a whole, but since the circuits of the two preamps are almost identical, I think it would be possible to switch in this way to dramatically reduce the number of tubes.

rv_switching_1.jpg

In theory, I don't think there will be any problems with the operation itself, but one thing I'm concerned about is that it seems like a big popping noise will occur when switching.
In my experience, switching the EQ/MV chain did not cause that much noise(marked in red). However, I think that the gain pot switching in the above circuit will cause a lot of noise(marked in blue).
When switching, the grid is in a 'floating' state without a fixed grid leak, so a large pop is likely to occur the moment it is reconnected to another gain pot.
In severe cases, temporary latency may occur I think.

How do you think about it?
If I switch the gain pot like that, will there be a huge popping noise or other functional problems?
Or will it just make a low or moderate level of popping noise and cause no major problems in operation?


The reason why I want to configure it like this is because I want to limit the number of preamp penthode tubes (12ax7) to 4, including PI, due to my production style.
Because I am greedy, I want to add a clean channel in addition to the two dirty channels.
For the Rockerverb, an independent 12ax7 is allocated to the clean channel.

rv_pre_dc.jpg

If switch the dirty channels as I mentioned above, I can make an amplifier with two dirty channels, including a clean channel and PI, with four 12ax7s.

If there are any other problems with this switching method, including the points I am concerned about, please advise.



p.s.

If there were serious problems with the above switching, I also considered this type of switching as an alternative.

rv_switching_2.jpg

In fact, I plan to do some modifications through testing for each channel, so I think this configuration is more advantageous from that point of view.
Although it is not possible to configure a clean channel with 4 12ax7 elements, Rockerverb adjusts the gain amount of the two stages through a dual gang gain pot, so it seems possible to use each dirty channel as a clean channel.

If I configure the switching as above, will I be free from popping noise? Are there any other problems besides this?

[jabguit]

The reason why I want to configure it like this is because I want to limit the number of preamp penthode tubes (12ax7) to 4, including PI

say what???

[psychepool]

say what???

I guess the sentence was unnecessarily complicated.


What I mean is that I want to configure a preamp using a total of three 12ax7s.

I am making amps in a small chassis of the same size, and there is not enough space to increase the number of tubes, so I want to make it with as few tubes as possible.

[Stevem]

That’s not what the first reply to your post was questioning.

You referred to a 12AX7 as a pentode when it’s not, in fact the whole large number of the 12A series of tubes ( 12ax7 av7, au7, at7 and others) are all duel triode tubes.
They can perform 2 separate amplification functions in other words.

[Snicksound]

I was interested in the composition of Orange Dual Dark, so I looked at the related circuits.
I can't find Dual Dark's official circuit, so I have to guess, but judging from the tube layout, I'm guessing that the Jim Root Terror and Dark Terror preamps are probably assigned to each channel and switched. (In other words, Rockerverb pre + Th30 pre)

In fact, the preamp circuits of these two are almost identical, with almost the only difference being the EQ.
Below is the Rockerverb pre.

rv_pre.jpg


Below is the Th30 and Dark terror pre.

th_pre.jpg
dt_pre.jpg


It is assumed that Dual Dark allocates each preamplifier circuit separately and switches it as a whole, but since the circuits of the two preamps are almost identical, I think it would be possible to switch in this way to dramatically reduce the number of tubes.

rv_switching_1.jpg


In theory, I don't think there will be any problems with the operation itself, but one thing I'm concerned about is that it seems like a big popping noise will occur when switching.
In my experience, switching the EQ/MV chain did not cause that much noise(marked in red). However, I think that the gain pot switching in the above circuit will cause a lot of noise(marked in blue).
When switching, the grid is in a 'floating' state without a fixed grid leak, so a large pop is likely to occur the moment it is reconnected to another gain pot.
In severe cases, temporary latency may occur I think.

How do you think about it?
If I switch the gain pot like that, will there be a huge popping noise or other functional problems?
Or will it just make a low or moderate level of popping noise and cause no major problems in operation?


The reason why I want to configure it like this is because I want to limit the number of preamp penthode tubes (12ax7) to 4, including PI, due to my production style.
Because I am greedy, I want to add a clean channel in addition to the two dirty channels.
For the Rockerverb, an independent 12ax7 is allocated to the clean channel.

rv_pre_dc.jpg


If switch the dirty channels as I mentioned above, I can make an amplifier with two dirty channels, including a clean channel and PI, with four 12ax7s.

If there are any other problems with this switching method, including the points I am concerned about, please advise.



p.s.

If there were serious problems with the above switching, I also considered this type of switching as an alternative.

rv_switching_2.jpg


In fact, I plan to do some modifications through testing for each channel, so I think this configuration is more advantageous from that point of view.
Although it is not possible to configure a clean channel with 4 12ax7 elements, Rockerverb adjusts the gain amount of the two stages through a dual gang gain pot, so it seems possible to use each dirty channel as a clean channel.

If I configure the switching as above, will I be free from popping noise? Are there any other problems besides this?

Never leave a grid without a ground reference during switching, or it'll be Sir Pop a Lot populating Pop City. Put a large resistor to ground (2-3M) after the switch to ensure constant ground reference for the tube that follows.

Also, this will have some interactivity between the drive pots. Paralleling two of them instead of just one with the other resistor changes the impedance scaling but also the bright cap gives a path to ground for high frequencies of the unused channel. So if you turn down the gain on one channel it darkens the other one.

[psychepool]

That’s not what the first reply to your post was questioning.

You referred to a 12AX7 as a pentode when it’s not, in fact the whole large number of the 12A series of tubes ( 12ax7 av7, au7, at7 and others) are all duel triode tubes.
They can perform 2 separate amplification functions in other words.

Oh! Right! Now I understand what is happening.
Just I used the wrong word. sorry.
As in the last answer, this means that I want to configure a preamplifier with three dual triods (12ax7).

Never leave a grid without a ground reference during switching, or it'll be Sir Pop a Lot populating Pop City. Put a large resistor to ground (2-3M) after the switch to ensure constant ground reference for the tube that follows.

I had the same thought, but since the grid leak is connected in parallel to pins 1 and 2 of the pot, I am concerned about a decrease of gain.
If I connect a value of about 2~3M, will there be a big difference in the amount of gain compared to when it is not connected?
If a value of about 10M is connected, it can be a measure of protection against gain reduction, but will it actually become the same as the unconnected state and popping will still occur?

Also, this will have some interactivity between the drive pots. Paralleling two of them instead of just one with the other resistor changes the impedance scaling but also the bright cap gives a path to ground for high frequencies of the unused channel. So if you turn down the gain on one channel it darkens the other one.

This is a problem I hadn't thought of.
In fact, another amp I made has a switching part with a similar configuration. (SloRectoTwin based amp)
I didn't notice any channel interference from the other channel's gain pot with this amp. I'll have to test it again sometime.

slorec_switching.jpg

Bogner Ecstasy uses the same type of switching and also has a bright cap, but it seems to avoid the symptoms you mentioned by sending the bright cap connection to the back end of the switching.

xtc_switching.jpg

[bepone]

@psichepool
sorry to be direct and realistic, but high gain amp is the most complex amp what is existing and you need to be very experienced to handle this.. pls buy some books first and read about the tubes..you are just jumping the steps with holes in knowledge.. you are falling on basics like grid resistors..saying pethode which i never hear from anybody in my life for ECC 12AX7 tubes......you need to develop it slowly and with practice, if you like this hobby.. take some time to read will be rewarding..

[psychepool]

@psichepool
sorry to be direct and realistic, but high gain amp is the most complex amp what is existing and you need to be very experienced to handle this.. pls buy some books first and read about the tubes..you are just jumping the steps with holes in knowledge.. you are falling on basics like grid resistors..saying pethode which i never hear from anybody in my life for ECC 12AX7 tubes......you need to develop it slowly and with practice, if you like this hobby.. take some time to read will be rewarding..

First of all I would like to say thank you for your answer.

I recently successfully built three high gain circuits. (XTC based, Recto based, Diezel based) Before making these, I had made several non-high gain amps. (Dumble 183, AB763 single channel, matchless ef86 15w, Plexi 6v6, etc.) It's not without its flaws, but at least it delivers the expected performance and the expected sound without any special noise.

Of course, I am not trying to say that I have many knowledge or high level of skill. I am not an electrical major, and I am still just a hobbyist who builds with fragmented knowledge. However, I feel like our conversation is going too far back due to confusion over one word, “Penthode.” I always post using the power of a translator, and in the process, unwanted confusion often occurs in words or sentences.

I'm in the process of selecting my next amp, and the Orange amp is one of the candidates.
Since I don't intend to do a 1:1 copy, I asked the question to check if there are any problems with the configurations I thought of based on my fragmented level of knowledge. As you said, I may not be at the level to do this, but I would like to have a conversation first. So far, we seem to have talked more about “Pentod” than the core content of the text.
Of course, making a tube amplifier is not easy and sometimes dangerous, so I think your advice is realistic. Thank you for your reply, and as always, I will look into more background information.

[bepone]

First of all I would like to say thank you for your answer.

I recently successfully built three high gain circuits. (XTC based, Recto based, Diezel based) Before making these, I had made several non-high gain amps. (Dumble 183, AB763 single channel, matchless ef86 15w, Plexi 6v6, etc.) It's not without its flaws, but at least it delivers the expected performance and the expected sound without any special noise.

Of course, I am not trying to say that I have many knowledge or high level of skill. I am not an electrical major, and I am still just a hobbyist who builds with fragmented knowledge. However, I feel like our conversation is going too far back due to confusion over one word, “Penthode.” I always post using the power of a translator, and in the process, unwanted confusion often occurs in words or sentences.

ok slowly, education no need to be high, self yes, practice is more important to develop what to put where, but build fundaments before. read at least this book, and many answers you can find there about tube operations and then proceed with experiments
https://www.lulu.com/shop/merlin-blenco ... pageSize=4

[psychepool]

ok slowly, education no need to be high, self yes, practice is more important to develop what to put where, but build fundaments before. read at least this book, and many answers you can find there about tube operations and then proceed with experiments
https://www.lulu.com/shop/merlin-blenco ... pageSize=4

It looks like a fairly thick book. I hope I can understand this book well. Thank you for the recommendation.