Project Ember Tube Rolling
2/5/2014- Blackburn Mullard 12AT7, France Philips Miniwatt 12AT7, and Holland Bugleboy 6DJ8
2/2/2014- Other Members Impressions Section Added
I just received my tube amp and did several hours of tube rolling. I could not decide if I wanted to do this or not, but after seeing that nobody had written about some of the tubes I was using on this amp I thought it may be helpful. I will be somewhat short and concise with each tube as I am not the greatest at describing the sound I am hearing, but my brother and my dad did confirm the same things I thought about the tubes (both being audiophiles as well, and these are my dads tubes). If you feel that one of my tubes descriptions is off. Feel free to question me, and I can go back and try it again. However some of these tubes my dad is only letting me listen to once due to the expense and/or rarity. If you need some clarification on tube models, let me know and I will get it clarified.
Tubes Accepted by Project Ember:Warning: Spoiler! (Click to show)
12V TUBES CONTINUED:
Anyways I tested 16 different tubes being a variety of 12AT7, 12AU7, 12DF7 (I will talk about this one later), 6N1P, and a 6DJ8. I tested each tube for about 30 mins, along with my brother and my dad listening to what I was listening to and pretty much confirming what I was listening to. Some people may say 30 min may not be enough to warm up the tube, but I did not hear any recognizable difference after 5-10 min of listening. Also some tubes were listened to much more than 30 min.
My set up was my DX100 (set at around 220 volume), using the line out (3.5mm to RCA), and using either the Alpha Dogs or my modded woody SR60is. The amplifier was set up at high gain low resistance for the Alpha Dogs and high gain, high resistance for the Grados.
The common songs (check spoiler for videos) used across all tubes were: Wintersun Time I: Sons of Winter and Stars for the amazing amount of instruments used in the recording, the variety of high, mids, and bass, great for testing along with it being an great recording. Metallica Black Album: The Unforgiven for its clean sound, and overall just a great rock song. Daft Punk RAM: Get Lucky for being an ok recording, along with being a decent song for pop and techno.
All songs were FLAC 16 bit 44.1 khz files ripped from CDs.Warning: Spoiler! (Click to show)
Sylvania Triple Mica: This tube had good detail, but I found the Mids and Bass a bit lacking. It was definitely a tube that had a good amount of treble. It was probably my favorite tube for treble as it had the best musical sound without being dull. I found the instrument seperation to be decent with this tube. This was not a great pairing with the grados due to the extended treble. The overall sound of this was a bit harsh, but not as harsh as some of the other treble tubes I have used.
Standard Sylvania: This was an ok all rounder tube. It was a decent flat presentation with ok detail, but not as much as some of the other flat signature tubes. It seemed to maintain the musicality of the triple mica, but a much more tame tube overall. Nothing about this tube was sparkly. It just ended up being an solid ok tube all around. Probably a good tube if you wanted a cheaper flat tube.
Telefunken: This was by favorite tube of the AT7 family I tested. It had the best details of all the tubes listed. It did not do anything bad nor did it do excel at any one thing (other than detail). It was my favorite flat tube, and probably the tube I will use the majority of the time. I did find the treble could be a bit harsh at times, but I think that is mostly due to the detail. My brother found this tube to be a bit tinny sounding, and my dad found the bass a touch lacking. However neither bugged me too much. As I found its other traits to pay off. This tube also had a really crisp sound to it. Just an great balanced tube over all.
GE: I personally did not like this tube at all. It seemed to have almost a slow decay to it. Along with a decent amount of sibilance. Had pretty bad mid range detail, with grainy sounding mids. It had ok treble, but was a bit harsh for my ears. It also had a decent amount of bass to it, but some of the other tubes had better bass.
Philips Miniwatt: Exactly what I wanted. This tube has the same construction as a Holland Philips tubes aka Amperex Bugle Boys I praised so well below. Well this tube has the exact same detailed airy smooth sound that I was searching for. The musicality on these is king to my ears. I highly recommend these.
Mullard Blackburn: I still am not the hugest fan on the Mullard tubes. They do an excellent job at mid range details, but I still find other parts of the sound signature lacking. It does have decent detail, but they do not match the musicality of the Amperex/Philips tubes.
12AU7A RCA Clear Top: Admittedly I hated this tube. I found it pretty hollow sounding, and dull. It had poor bass and was lacking mids. The best thing about this tube was the treble, but I felt like there were other tubes that did treble much better.
Mullard CV4003: I found this tube a bit lacking in bass with poor mid range detail. However it had good details and good treble with little sibilance. Overall I found this a decent tube despite it not excelling at anything, and having some faults. I found it to be an easy listening tube.
Family Notes: These tubes are probably not full optimized in this circuit as they sounded slightly dull. My dad stated that they did not carry all the characteristics from when he used it in his MC60 amps.
Westinghouse: This was an great tube. It had good detail, but less than some of the other very detailed tubes. It shared a lot of the qualities of the Telefunken. It was well balanced. It had a bit better bass than the Telefunken, with an airy quality. In my opinion this an easy listening version of the Telefunken. If you felt like kicking back and did not want to listen to all the details, this would be the tube to put in.
Family Notes: This is most likely a very hard tube to find. My dad stated it was a very strange tube he found on ebay, and bought a quad to test. He did not like it in his MC60 amplifiers, but really liked it in the ember. So the circuit in the ember may have good optimization for this tube. This tube is supposed to be a cross between a 12AX7 and a 12AT7 I believe (it could be the 12AX7 and 12AU7 if I am not remembering correctly). I am not sure if any other companies developed these tubes.
Tesla E83CC: This tube had reduced treble, but had a great mid range to it with very good mid bass punch. It did not excel in either bass nor treble. This would be a great tube for someone who loves mids.
Mullard CV4004: This particular tube was amazing with Daft Punk. This would be the tube to buy if you wanted an upgraded Mad Dog sound signature and owned the Alpha Dogs. It gave it a bit darker presentation, with good mids and decent bass. It was lacking a bit in treble, with a bit more sibilance than other tubes. The sound stage sounded a bit reduced. Overall this was a decent sounding tube.
GE Longplate: This tube did not seem to excel at anything. It had poor separation and lacked detail. It had ok treble, but I would not purchase it for the treble as there are better tubes out there for treble. I personally would not recommend this tube.
RCA Black Plate: I found this tube to be a bit lacking in the mid range. It was a very harsh and dry sounding tube. I thought it had decent instrument separation. I did have great treble. This overall tube gave my Alpha Dogs the presentation of the AKG K701 (in which I am not the biggest fan of). Even though it was not my favorite it would probably be a great match for some one who loves treble.
Standard 1970s RCA: This tube had good midrange, but had poor separation and soundstage. It had decent detail and treble. However it had a decent amount of sibilance. This is an ok tube, but there were others that I liked better.
Mazda III-8: This tube had the best bass of all the tubes. So if you wanted a bassy tube this would be the tube for you. It had decent mids. The biggest downfall of this tube was the treble as it was harsh and sibilant.
Holland Amperex Bugle Boy: This was my favorite tube of all the tubes I tested. Sadly I can not keep or use this tube ): anyways this was the only tube that matched the Telefunken in detail. This tube had decent separation with good treble and mids. The bass was a bit lacking. This tube had the airiest sound of all the tubes by far. It was a very smooth sounding tube over all. I highly recommend this tube if you can afford one.
GE: This tube was pretty harsh with a good amount of sibilance and lacking treble. However it had good detail, and good mids including the midbass. It has a slightly poor separation overall. It had decent bass quantity as well. Overall a solid tube that really had some positive traits to it.
Holland Amperex Bugle Boy: This tube share a decent amount of similarities of the Philips 12AT7 and Bugle Boy 12AX7 however I did not find it as airy as either of the tubes, nor as smooth. I also did find that the bass was not as good and was not as punchy. However I did find a sweet spot on the volume pot where the tube did sound a bit better. I tested this on both the Grados and the ADs, and still preferred the 12AT7 and 12AX7 tubes. To be fair though, it is hard to match volume of two different gain tubes.
Gold Grid: This is the stock tube that the amp was shipped with. I got to admit it was a bit of a disappointment. I personally did not like the sound signature of this at all. This had the warmest sound of all the tubes, with poor instrument separation. The mid range was ok, but I found this tube to have poor detail. I personally recommend buying a different tube to use with your Project Ember.
My Tube Rankings (from best to worst):
Amperex Bugle Boy 12AX7
Sylvania Triple Mica 12AD7
Mullard CV4003 12AU7
Standard Sylvania 12AT7
Tesla E83CC 12AX7 tied with Mullard CV4004 12AX7
Standard RCA 12AX7
RCA Black Plate 12AX7
GE Long Plate 12AX7
Gold Grid 6N1P
RCA CLEAR TOP 12AU7
Other Head-Fi Member's Tube Impressions
(If you do not want your impression added just say so in your post)
6DJ8 Amperex Bugle Boy- Smooth with huge soundstage
6DJ8 Amperex Orange Globe- Slightly less soundstage than the Bugle Boy, but was slightly clearer with a touch more details.
12AX7 Sylvania Triple Mica 5751- An industrialized 12AX7 (gain 100) with a gain of 70. Due to higher gain, this one emits a 60 HZ constant level hum. A GE 5751 was not as prone to do that. To remedy that, I made a tube shield out of aluminum foil and slipped it over the tube--noise gone. This one produces a very robust, dynamic sound, much like solid state with the tube benefits.
12AX7 Amperex 6201- is very warm and liquid with a tight although not powerful bass. Mids are very warn and highs mellow. It is a very "tubey" sound. The imaging seems like being in a sound proofed chamber, being surrounded by the instruments.
Tungsram E80CC-Good range,stage is a bit narrow
Westinghouse 12au7/ECC82 black carbonized plates tube raised -getter- best so far, good sound, stage
Edited by gamefreak054 - 2/5/14 at 6:26pm