Need help again. I just got the new EH 6922 tube over the weekend, but today, I found out it has very loud hissing sound ... is that the tube is done? |
Well ... harsh may not be the right word, but maybe due to some of the recording, some song has very strong glare ... I don't know if it is the right word also. Usually when hearing female vocals. The bottom line is, got fatigue after hearing for a while. Some recordings are ok. Anyway ... just want to try out some other tube to see if it will improve the sound to my taste. |
i finally got the Electro-Harmonix-6922 and listened for an hour, so far, I like it. it doesn't have the glare as in my previous 6h23neb. I also feel the detail and sound stage are improved |
Thanks. I am reading Joe's tube Lore page. He also recommend the Amperex white label PQ 6922. I found a couple posting on eBay, but it is not matched pair and are expensive, average to be $180. =(
I am very new to tube. So, all those Amperex tubes are old, and can only get from eBay? I tried search the tube store, but can't see any of them. |
I am very confused. So, the Amperex 6922 is not good? From the AI FAQ, it says:
"Only "mil-spec, low-noise" 6922, 6DJ8, 7308 or European E88CC tubes are recommended for use in Modulus preamplifiers.
Previous production Modulus M2, M3, M3a and L1 preamplifiers used Russian 6922 tubes. While quality and sonic performance of these tubes were excellent for several years it is unfortunate that current-production from the Sovtec/Reflector factory does not have the same sonic identity and a high percentage prematurely fail.
Current production Modulus M3a and L2 Preamplifiers use a Russian Military Type 6922 with "Grey Plates" and have excellent sonics and reliability.
Similar tubes which have different technical specs should not be used.
7DJ8 tubes require higher filament voltage and performance is marginal.
6NIP tubes should not be substituted as they require additional filament current and their use will compromise performance."
So, the 7D8J and 6N1P conflict with Joe's comment. And Joe said 6922 is not suitable? ... So, the remaining choice are:
6h23n, 6DJ8, 7308, E288CC ? |
thanks for the advice. I will try turn on the cap. It is currently turn off based on recommendation from AI. It won't hurt to try turn it back on. Actually, what is that cap thing?
Also, the Electro-Harmonix-6922 seems worth a try. Not expensive, and it says it may help to remove some of the harshness.
My friend came over and he have a better word to describe other than harsh. It is "dry". It is hard to describe, but when he said this word, I feel it describes the sound. |
Hi Dekay,
How does the Siemens 7dj8 sound in the M3A? Would it help to smooth things out a bit compared to other tubes? I have ordered Electroix-Harmonix 6922. Any experience how they would compared? |
I tried to turn on the capacitors, my immediate impression is that it sounds thin, and not as musical. It seems it is easier on listening though. But it then sounds closer to the Rotel I have before ... |
Here is my system:
Sony Blu ray player, Maverick audio DAC (not using the tube buffer), AI L1 preamp, McCormack DNA-1 deluxe amp, B&W CDM9NT speaker.
I am using the Aux input, and Main 1 output. I will try using the Main 2 to see if there is any different.
Also, I have the speaker wire inverted. I have the caps turn off before as recommended by many others. I tried to switch them on last night. I agree that it is more neutral and easier on ears. I will try turning it back on and Main out 2 to see who it sound. |
I tried different combination.
Caps on with Main 1 out - harsh or dry
Caps off with Main 1 out - sounds thin, less musical, but easier on listening
Caps on with Main 2 out - it seems it improves the situation a bit, not as harsh. Or according to the manual, it removes tube glare.
I prefer to have caps on and Main 2.
Per the previous owner, the tube is Russia military grade 6h23neb with less than 50 hrs.
I also tried switching the left and right tube, but the buzzing noise is still louder on the left channel, so, it is not because of the tube. It is not a big deal, can't hear it at the sofa.
I am egar to try out the 6922 and see how it sound. |
Thanks for the advice. I don't think it is because of the interconnect though. I got the noise since the first day I got this preamp, then I upgrade the interconnect, and the noise is still there. Maybe some capacitor are old? Inside, there is a sticker says it is checked in 96. So, it is a 14 years unit. Is it about time to have a service and replace some capacitor?
I did some more listening, the Main 2 out seems work for me. It remains musical with good sound stage, and the harshness or glare is improved. |
I emailed Upscale audio, but with no reply. I am disappointed. I even pay extra $10 for the premium, and it says on the web site that this is a tube they would recommend.
But BTW, can I tell if it is the tube comes defective, or it failed prematurely? I hear intermittent hissing sound. |
I tried plug and unplug several times, and it is still there. And it is not intermittent anymore, it is a continuous hissing sound. I also switch the left and right tube, and the hissing sound move with the tube. By this, I can confirm one of the tube failed. The other is still ok. So, usually, a tube won't fail this fast, is this covered under any warranty? |
I contacted Upscale audio and they agree to send me a replacement tube. Excellent service, way to go, Upscale. |
