Yup , this is the conservative values found by a lot of people. The negative output current compliance makes the grid of the tube the ideal input with something 100 to 300 R grid stopper resistor.
One should use better tube than 6NP2 though. I would avoid the pre amp delirium and just use a good no microphonic tube with a mu >30 and leave th e pre to make the rest.
I was watching that exact device on ebay. It is designed to use a line level input voltage that is many times greater than the output voltage of my DAC chip.
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Try ECC88 or 6N23P-EV instead. E188CC/7308 if you can. There are a lot of threads here about tda1541A and tube stages. Thorsten Loesch made some advices in the big TDA1541A thread (look from june 2024 his posts there, one is about tubes with less expensive ref and also suited for the task).
Nothing should stop you to try the E88CC and 6922, but they are more microphonic and more shooty when aging (trebles?)
Nothing should stop you to try the E88CC and 6922, but they are more microphonic and more shooty when aging (trebles?)
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I think I have an excellent vinyl system: Yamaha PX-2 with Ortofon Cadenza Black cartridge and CAT SL1 Signature MkIII with phono stage. I no longer have enough money to improve on it other than some minor DIY tweaking.
I really have no expectations regarding how this experiment is going to sound. I wanted to see how eliminating the IC op amps (NE5532) in my Philips CD880 player would sound. This experiment might sound better or it might sound worse but the only way to find out is to build and install the circuit that MarcelvdG designed for me and push play on my CD player.
I intend to do four comparisons:
1. My Philips CD880 with no mods.
2. My CD880 with a discrete high end op amp that I bought from Sparkos Labs.
3. My CD player with no op amp and this experimental circuit feeding my preamp phono stage.
4. Build a Lampizator and install that to my CD player.
Whichever of these 4 sounds best will be compared to my Marantz CD94 MkII, Marantz CD95 and my Mark Levinson 390S. The one that sounds best will become the one I keep and I will sell the others. I have collected too much stuff in the last 40 years.
I am 78 years old and have an income that is about 1/2 of what I earned before I retired.. My HF hearing isn't as good as it was when I first began my quest to put together the best audio system I could afford. It is time to just listen to the music I love and enjoy it before I die.
I have a few Amperex 7308 PQ (about 6) and one pair of Reflektor 6N23P 1975 SWGP Silver Shields NOS that I bought before the prices went completely beyond sanity. My preamp uses six E88CC type tubes (3 in phono and 3 in line stage). I have quite a few NOS 6922s and Mullard 6DJ8s. I also bought a stash of quite a few 6N23P-EVs about 8 years ago because my amp uses five 6922s in addition to the six my preamp uses.
That's strange. The E88CC is the special quality version of the ECC88. It should be very similar to but more reliable than the ECC88.
In my book the E88CC is made for industrial like the 6922 either (used for comutation). The SQ I blieve is for the longer span life, but for audio, many noticed the ECC88 was better. It is what you can read here and there...
E88CC and 6922 are close but not the same than the ECC88/6DJ8 as far I know., but of course same family. With time the trebles are climbing so the construction is not the same and less usefull for the audio... market is another thing. Some prefer some special constructions of the E88CC and 6922, but imo it was surely because the ECC88/6DJ8 were harder to get.
E188CC/7308 has not that default and is a super ECC88 with special parts sorted out for SQ too (and higher V possible) but mainly to be less microphonic and paired between to the two triodes 5% max. Just better everywhere.
E88CC and 6922 are close but not the same than the ECC88/6DJ8 as far I know., but of course same family. With time the trebles are climbing so the construction is not the same and less usefull for the audio... market is another thing. Some prefer some special constructions of the E88CC and 6922, but imo it was surely because the ECC88/6DJ8 were harder to get.
E188CC/7308 has not that default and is a super ECC88 with special parts sorted out for SQ too (and higher V possible) but mainly to be less microphonic and paired between to the two triodes 5% max. Just better everywhere.
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From Joe's Tube Lore:
quote "The 6DJ8 family was originally developed by Amperex. The first tube in the family was the bare steel pinned 6DJ8 followed by the gold plated pinned 6922 and 7308. These latter two were premium versions rated as 10,000 hour life tubes. The 6922 was a premium industrial version and the 7308 was the top of the line guaranteed low noise version... The Europeans used different model numbers to identify these tubes, by the way. In their numbering system the 6DJ8 was an ECC88, the 6922 was an E88CC and the 7308 was an E188CC" end quote
The ECC88 (6DJ8) was the most common type in the family. It had a much lower life expectancy and much lower spec requirements than the two below. It also cannot tolerate the higher voltages that the two below can. For this reason, it cannot always be substituted in circuits designed for 6922s or 7308s.
An E88CC, is the European designation for a 6922 which was made to be the industrial upgrade, to a ECC88. It is a higher spec tube, than the ECC88/6DJ8; lower noise & microphonics, longer longevity, lower failure, higher voltage capabilities.
The E188CC (7308) is the top of the types in this family. It was more closely selected for spec consistency. The 7308 had more stringent tolerances with matched triodes, and was intended to be more used for the most demanding applications. It also had the least noise and microphonics.
All of that said some 6DJ8s sound great which is why we roll tubes in our gear. You never know what tube will please you with a surprise.
quote "The 6DJ8 family was originally developed by Amperex. The first tube in the family was the bare steel pinned 6DJ8 followed by the gold plated pinned 6922 and 7308. These latter two were premium versions rated as 10,000 hour life tubes. The 6922 was a premium industrial version and the 7308 was the top of the line guaranteed low noise version... The Europeans used different model numbers to identify these tubes, by the way. In their numbering system the 6DJ8 was an ECC88, the 6922 was an E88CC and the 7308 was an E188CC" end quote
The ECC88 (6DJ8) was the most common type in the family. It had a much lower life expectancy and much lower spec requirements than the two below. It also cannot tolerate the higher voltages that the two below can. For this reason, it cannot always be substituted in circuits designed for 6922s or 7308s.
An E88CC, is the European designation for a 6922 which was made to be the industrial upgrade, to a ECC88. It is a higher spec tube, than the ECC88/6DJ8; lower noise & microphonics, longer longevity, lower failure, higher voltage capabilities.
The E188CC (7308) is the top of the types in this family. It was more closely selected for spec consistency. The 7308 had more stringent tolerances with matched triodes, and was intended to be more used for the most demanding applications. It also had the least noise and microphonics.
All of that said some 6DJ8s sound great which is why we roll tubes in our gear. You never know what tube will please you with a surprise.
Long off thread topic story :
It was a serendipitous surprise that led me on a 30 year quest to find more of a particular tube. My first and second CAT SLL1 preamps used a pair of 12AU7s in the line stage. As a newbie to tubes I decided to try tube rolling. I bought an NOS pair of Mullard 12AU7As off thread topic (after determining that they were subs for 12AU7s in my preamp). I put them in and I was like WOW, everything just sounds better, particularly the "smoothness" (if that is a quality by itself). At first I thought maybe it was just because the tubes in my preamp were too worn. I bought a lot of NOS Mullard 12AU7s and 7As after that expecting similar results. Being a tube newbie, I didn't understand all of the things that make this or that tube sound different. After buying about 20 Mullard 12AU7s, I began to realize that many sounded different in different ways and none sounded like my "magic" pair.
So, I began to read a lot about what can make one tube sound different from another even from the same manufacturer. One day, I was looking at my two "magic" tubes and all the others that I had bought. I noticed that the little pins sticking trough the white disks were copper colored instead of silver colored. I thought maybe that is why they sound different.
Strangely, I also found that all of the Mullard 12AU7s but none of the 12AU7As that I had had the copper grid pins and the 12AU7s had lighter color grid pins. I read that the little pins were the tips of the grid rods, So, I made a search for Mullard 12AU7As with copper grid rods. I finally got another pair of used 12AU7As with the copper pins but they were really hissy in my preamp. I kept searching for more. It took me over a year to get another one. I was getting tired of looking at ad photos of tubes to see if the pins looked copper color. That is when I learned about date codes. The date codes on the five I had all were 3 digit codes from Blackburn. Then, I noticed that they were from B0B to B0D. I turns out that the tubes with the copper grid rods were only made over a 3 month period (B0B, B0C, B0D) when Mullard made their first 12AU7As. BTW, this isn't a case of rarity causing a tube to create great expectations because when I fell in love with this tube I had no idea that it was rare and in the past 30+ years I have never seen any mention of it being a great but rare tube to seek.
Over 30 or so years I only managed to buy 10 total of those tubes. All sounded hissy except another NOS pair I had found. So, I had found what I believe to be the best sounding 12AU7 or 12AU7A tube (and I tried many of the variations in the family) but the one I loved is more rare than hens teeth. I am so glad that my current CAT SL1 model does not use 12AU7s. 🙂
It was a serendipitous surprise that led me on a 30 year quest to find more of a particular tube. My first and second CAT SLL1 preamps used a pair of 12AU7s in the line stage. As a newbie to tubes I decided to try tube rolling. I bought an NOS pair of Mullard 12AU7As off thread topic (after determining that they were subs for 12AU7s in my preamp). I put them in and I was like WOW, everything just sounds better, particularly the "smoothness" (if that is a quality by itself). At first I thought maybe it was just because the tubes in my preamp were too worn. I bought a lot of NOS Mullard 12AU7s and 7As after that expecting similar results. Being a tube newbie, I didn't understand all of the things that make this or that tube sound different. After buying about 20 Mullard 12AU7s, I began to realize that many sounded different in different ways and none sounded like my "magic" pair.
So, I began to read a lot about what can make one tube sound different from another even from the same manufacturer. One day, I was looking at my two "magic" tubes and all the others that I had bought. I noticed that the little pins sticking trough the white disks were copper colored instead of silver colored. I thought maybe that is why they sound different.
Strangely, I also found that all of the Mullard 12AU7s but none of the 12AU7As that I had had the copper grid pins and the 12AU7s had lighter color grid pins. I read that the little pins were the tips of the grid rods, So, I made a search for Mullard 12AU7As with copper grid rods. I finally got another pair of used 12AU7As with the copper pins but they were really hissy in my preamp. I kept searching for more. It took me over a year to get another one. I was getting tired of looking at ad photos of tubes to see if the pins looked copper color. That is when I learned about date codes. The date codes on the five I had all were 3 digit codes from Blackburn. Then, I noticed that they were from B0B to B0D. I turns out that the tubes with the copper grid rods were only made over a 3 month period (B0B, B0C, B0D) when Mullard made their first 12AU7As. BTW, this isn't a case of rarity causing a tube to create great expectations because when I fell in love with this tube I had no idea that it was rare and in the past 30+ years I have never seen any mention of it being a great but rare tube to seek.
Over 30 or so years I only managed to buy 10 total of those tubes. All sounded hissy except another NOS pair I had found. So, I had found what I believe to be the best sounding 12AU7 or 12AU7A tube (and I tried many of the variations in the family) but the one I loved is more rare than hens teeth. I am so glad that my current CAT SL1 model does not use 12AU7s. 🙂
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That's funny Joe's tube Lore is writting it as if Amperex had invented the ECC88 and ECC88 is just the name took byy the european of the 6dj8 !
ECC88 (beginning of 50s')was invented before the 6DJ8 (1958) by Amperex. The 6DJ8 was an upgrade of the 6BK7. But as Amerex was bougth by Philips in 1955. It is not clear who given to the other. But for sure that is Philips in Netherland that developped first in the beginning of the 50s', certainly 6DJ8 was made on an ECC88. Then development were merged. I think the new equipment was from Philips and sent at NYC. Btw Philips Europe was sometimes make 6DJ8 for the US or sended ECC88 according the fab facilities and market . Some others jumped on the Bugled boy that was just a marketing thing logo...
6N23PE was the cheap counterfact USSR with some cheap building tricks to copy it. More dispersion, different heater voltage, less life span. The EV was better (lessmicrophonic). Indeed some liked the non EV silver thing, but it was mainly because a guy said that then people followed and there was a spread on that model.
That's a nice collection of gears you have audioxcell !
ECC88 (beginning of 50s')was invented before the 6DJ8 (1958) by Amperex. The 6DJ8 was an upgrade of the 6BK7. But as Amerex was bougth by Philips in 1955. It is not clear who given to the other. But for sure that is Philips in Netherland that developped first in the beginning of the 50s', certainly 6DJ8 was made on an ECC88. Then development were merged. I think the new equipment was from Philips and sent at NYC. Btw Philips Europe was sometimes make 6DJ8 for the US or sended ECC88 according the fab facilities and market . Some others jumped on the Bugled boy that was just a marketing thing logo...
6N23PE was the cheap counterfact USSR with some cheap building tricks to copy it. More dispersion, different heater voltage, less life span. The EV was better (lessmicrophonic). Indeed some liked the non EV silver thing, but it was mainly because a guy said that then people followed and there was a spread on that model.
That's a nice collection of gears you have audioxcell !
I also always thought the PCC88 and ECC88 were originally from Philips, but I can't remember what that is based on.
There is no evidence wikipedia is a proven source. It is not an encyclopedia made by the best sources but written by anyone. Same for AI, they just compil things writted on Internet.
Again many sources indicate than the 6dj8 cames later in 1957.
Who knows really, we must be prudent.
How is written Audio paragraph and the whole is mainly BS and a good illustration of rewritten history by dummies and fake woke plot rectification oriented. And 6dj8 was made on philips tooling. 6NP23 is not a direct remplacment as for the 6922. Close but different values needed.
Again many sources indicate than the 6dj8 cames later in 1957.
Who knows really, we must be prudent.
How is written Audio paragraph and the whole is mainly BS and a good illustration of rewritten history by dummies and fake woke plot rectification oriented. And 6dj8 was made on philips tooling. 6NP23 is not a direct remplacment as for the 6922. Close but different values needed.
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Usually Wikipedia pages have links to references, but the only reference on this page is "6DJ8 tube data at DuncanAmps".
One could browse through all the old valve advertisements on r-type.org, but I don't intend to do so.
One could browse through all the old valve advertisements on r-type.org, but I don't intend to do so.
Well there is a difference between ref took by specialists from specialists in Quo Vadis or Britanica and anyone that choose any ref he chose w/o knowledge to bless his so-so feeding Wikipedia contributiion (which is lipstick on a pig). Even now students less and less read and uses AI, they believe in bible the same way w/o a sparkle of method anymore or almost, as if Spinoza never existed (pun intended as he cames from Holland) because too difficult to read... Ah 10 pages at once : too hard, better Cecil B. DeMille. That's how you beginn to see philosphia rewritten by incompetent people or History remade for dummies at the TV and more and more in universities/college. Form w/o substance ! 🙂
Anyway audioxcell have the most interressant tubes to make a good tubes stage for the TDA1541A. I would lurk more at Loesch work for tube + TDA1541A work as he begunn about that long before Lukaz and not with east or chineese tubes (less good and often copies of the westerns')
Anyway audioxcell have the most interressant tubes to make a good tubes stage for the TDA1541A. I would lurk more at Loesch work for tube + TDA1541A work as he begunn about that long before Lukaz and not with east or chineese tubes (less good and often copies of the westerns')
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According to this E88CC (or CCa) was the first of this family:
https://www-jogis--roehrenbude-de.t...milie.htm?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=en
https://www-jogis--roehrenbude-de.t...milie.htm?_x_tr_sl=de&_x_tr_tl=en&_x_tr_hl=en
LOL ! CCa are even not real E88CC,getterwas simplified by Siemens but is it less good (for our purpose). As said E88CC is not an ECC88 and was not made for the exact same purpose.
Anyway you must be rigth, all of thisis mythic and Internet the new bible, wonder if the states are ruled by people reading internet now ? Well, let's back to the topic.
Marcel approach is interresting as usual ! 🙂
Anyway you must be rigth, all of thisis mythic and Internet the new bible, wonder if the states are ruled by people reading internet now ? Well, let's back to the topic.
Marcel approach is interresting as usual ! 🙂