Since I pay special attention to brilliance, detail, air and soundstage I found the Melz 6SN7 1578 from 1954 and the Melz 6SL7 with oval Micas to be the best match for my configuration. The rest is (still) Line Magnetic original.
Anyone running Melz 6H8C or 1578 on 508IA? How many hours have you ran them before the sound settled? I found them to be quite "edgy" from high to low in my system, sounded very unnaturally. BTW, pairing with ECC35, ACME 805, KR300B and on NFB 3. So far, have only burned in 2 pairs (have 4 different pairs) for about 8 hrs each, and could hear there is an improvement but by not much. Please share your experiences. Thanks!!!
I am starting to agree with you...lol After trying a pair of '56 Melz 6H8C and a pair of '76 Melz 1578 with 8 hrs burned in time each, I am quite hesitate to run them further. They just sounded too unnatural, with forced sound from high to low. They are out of my system for now, perhaps I would run them again in the future, hoping sound will improve after further burn in when I have the patient. Have another 2 pairs ('75 Melz 1578 & '80 Melz 1578) waiting to be burned in as well.
There's no tube burn-in. Did you see my post about what the real actually good MELZ should have as indications they're the genuine article?
Found it, it is at post#28 and yes, I have a pair of the real '76 Melz 1578 (the others are not) that fit exactly your descriptions, perhaps it is just not suited to my taste, at least not in my system...thanks!
You're quite welcome. Which tubes do you have in each section? I'll be able to suggest far better ones.
Currently, I am switching between 6SL7: RCA 5691 Mullard ECC35 6SN7: Mullard ECC33 Ken-Rad VT-231 Sylvania VT-231 RCA VT-231 NU 6SN7GT (Yeah, I know I am greedy...lol but all of them sound so good, cant resist. At least I dont have so many GF) With ACME 805 & KR300B
...but the asking price is just too crazy for me to swallow, I would rather get another pair of 300B. Received a quote from JAC on EML300B XLS, still thinking should I proceed or should I go for TA-300B instead?
Sell what isn't used. You've got enough to buy 2-3 pairs, easily. 300Bs don't have close to the same impact on SQ. It's a waste of time and money to start there. Get the right 6SN7s to start and you'll have the best foundation with the most difference in SQ for the money. You can either listen to my experienced advice or try to improvise. I don't personally quite understand buying a ton of tubes when you just need the right ones. It's wasted money. The ECC32 kill everything else super easily. It's not even close. My friendly advice.
Greatly appreciated for your kind advise. What price point do you think is reasonable for a pair of ECC32 now? I have seen quite a wide range on EBay. There are bn base n bk base, ECC32 n CV181, any particular one I should get?
Thanks. I did open the chassis to look for any loose connection a while back but I am not sure if the pop happens due to this. It happens only with ACME 300b and not the stock. I don't have another pair of 300b to try it out. The meters are also stable and doesn't loose bias.
Are those RCA VT-231 black glass? How do you find them against the other 6SN7/VT-231 you have tried? I've tried NU 6SN7 black glass, but I liked much more Sylvanias VT-99 (with adapter).
No, it is smoked glass black base. So far, all of these 6sn7 I have sound good to me, just with different characters. It is a matter of matching for what music genre. Cant say the same for Melz 6H8C n 1578 though.
Are ECC33 also suitable for 6SN7 replacements, i've read conflicting advice on this but just seen some going at a decent price ? Also would £250 be a good price for a matched pair of Mullard ECC32 black base ? Are these Marconi Pro Comm Italian tubes any good, some of the other Marconi tubes go for silly prices ? *RARE* ITALY MADE NOS NIB Matched Pair Marconi (FOR PRO COMM) 6SN7GTB 6SN7 Tube | eBay
From my understanding, ECC32 & ECC33 are acceptable for LM-508IA (note: not all amp) though they are NOT considered as a direct substitute for 6SN7 due to different specs. So, use it at your own risk.
"ECC32" and "CV181" are one and the same. CV181 was the military designation whereas ECC32 was the consumer designation. Black and brown bases only indicate the period of manufacturing. In my experience, there was no change in SQ when switching between them. However, bottle shape can though I've never been able to switch between two models, one with a short and the other with a long bottle. Those who have indicate the long one can sound a little bit better but it is merely a subtle improvement. As for the price, that is really up to how much you're willing to spend. There are some deals to be had if you're patient. I got a pair from a dealer last year in the US for $500. I wanted an extra one, they shipped it, and it never moved. They refused to do anything about it such as initiating a trace via the post office so after 3 months of waiting, I requested a refund. Good thing I paid through PayPal which made this easy. I was refunded, told I bought the last one, and that there were no more Mullard ECC32s available, yet they never edited the webpage which still allows for people to buy some. It is still possible to submit orders for this product. If the orders are accepted, either there was a miscommunication on the onset or they got additional stock. Keep in mind that their products are oftentimes not true NOS but they do measure as NOS. In reality, they should be advertised as ANOS but since most people don't know what that acronym means, most dealers advertise as NOS only. Mullard ECC32 / CV181 I've recently bought an ANOS one on eBay for $225 US and it is now in transit? Why? Because it can also be used in the 6SL7 slot and I wanted to experiment the SQ difference between it and the ECC35 I currently have in there. According to @adamaley using an ECC32 in the 6SL7 slot is even better than an ECC35 so once I saw an auction from a reputable seller for a Mullard ECC32pop up, I went for it. Worst-case scenario, I'll have a spare tube in case one of my ECC32s in the 6SN7 slots dies or becomes defective/microphonic. I can confirm the Mullard ECC33 is a direct replacement for the 6SN7 slot in this amp. They are very good and nearly identical in sound to the Tung-Sol 6SN7GT with round black plates. That would be my 2nd choice but the Mullard ECC32s are so much better that the Mullard ECC33s or Tung-Sol 6SN7GT with round black plates come in at a distant 2nd. That sounds far too good to be true. Usually, that price is for a single tube! Ensure it's from a reputable source and pay only using PayPal if you ever decide to buy them to be on the safe side. Do you have any pics to share for this pair? A lot of people sell tubes like this without really knowing what they have. They might be advertised as Mullard ECC32s when they're something else. Almost all Marconi tubes convey ridiculous prices. I've almost never have read any reviews on them likely due to the small pool of people who can afford them. I personally wouldn't bother with them. There are a lot of tubes with ridiculous prices that do not sound like anything special. Price is determined by rarity and/or demand. Do not confuse price with SQ performance.
Thanks a very informative and useful reply, you were correct it was £250 for a single ECC32 Mullard when i enquired further, i will keep an eye out for Tung-Sol 6SN7GT also.
I have a pair of those, although one tube emits some strange static here and there. If you're interested, I could sell the pair to you at half the cost so you would just need one more tube if you enjoy the sound. If you don't, you won't be out as much money and would just need to sell that one good tube. Let me know.
Thanks for the kind offer but i live in UK and any postage costs would proberbly negate any savings, a matched pair seem to be about £100 ish judging by ebay at the moment ? plus ive just paid out this afternoon for a new av center speaker i want to do a little diy up occ wiring job on.
Be careful! Again, there are plenty of sellers who market their wares inaccurately, oftentimes on purpose. Show me pics and I'll be able to tell you if it's the genuine article. Normally, the price for these is *much* higher than what you quoted, closer to 3x that amount! Lastly, I have a business account with the post office so my rates are good to ship to the UK. Keep that in mind.
Has anyone tried Tungsram 6SN7GT? It seems that there isnt any kinds of useful info on the internet at all. Please share your thoughts if you do, thanks!!! 2x 6SN7GT Tungsram NIB Identicall Tube Valve | eBay
I picked up a pair of Psvane ACME 805's from @Chris Amott recently and I'm liking what I'm hearing. I swapped out my vintage RCA 805 JAN tubes to see how these well regarded ACME's would compare. The ACME's are delivering a more richly textured sound with a bit more warmth, but they don't sacrifice the punch nor the detail that I really enjoyed with RCA's. The ACME's don't deliver the hyper clean presentation that the RCA's provide but the textured sound is overall a pretty significant sonic improvement to my ears. The RCA's also required turning the bias adjustment up quite a bit compared to both the stock 805's and the ACME's. After dropping the ACME's in the bias was reading 145 mV so I had to dial it back down to 120 mV. I noticed this same dynamic with the stock 805's. It's probably the reason why the RCA's deliver such a clean, powerful slam but overall the ACME's are more musical. Thanks again to @Chris Amott for making these tubes available.
