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Tube rolling the LITTLE DOT I+ for use with the Grado SR225 headphone

post #1 of 39
Thread Starter 
I just returned from a trip. Not by car. Not by plane. Not by boat. My trip was on a Grado SR225 headphone plugged into a Little Dot I+ fitted with Sylvania GB-408A (nickel plated pins, not gold) vacuum tubes and an LT1364 operation-amplifier.

I have just listened to various pieces of music comparing the Western Electric 408a vacuum tubes Sylvania GB-408A vacuum tubes on the Little Dot I+ headphone amplifier.

Western Electric 408a vacuum tubes
Preliminary comparison of the two vacuum tubes will give the impression that Western Electric 408a vacuum tubes are clearly superior to the Sylvania GB-408A vacuum tubes. The Western Electric 408a vacuum tubes project airy presence and a wide-open sound stage. The sound is precise, transparent and brilliant. The encounter was like a personal Aurora Borealis light show. Instruments dazzled like light shooting across a starry background, changing expressive colors before my ears.

Sylvania GB-408A vacuum tubes
Liquid midrange. It poured into my mind. "Did I just take the blue or the red pill?" I no longer listened to the music. It now possessed me. Transported to another plane of existence, each pluck on string and stroke of bow reverberated into me and sent me farther and farther away. I was no longer looking at a sky. I was transported beyond it. A voyage. Walking across glass. Each resonance felt like steps on fracturing ice. Song became fragile and emotional.

At the end of one song, I thought to myself, “Perhaps I should return to the Western Electric 408a vacuum tubes.” So I put them in and sure enough, a good solid-state like sound returned. Detailed, crisp and quite good.

However, not all headphone amplifiers play well with the Grado SR225 headphone. I often complain about its piercing highs. I have been experimenting with different amplifiers that might tame the highs. (The Meier Corda Headsix that I just sold could do this.) The Little Dot I+ with Western Electric 408a vacuum tubes, every so often the highs of the Grado SR225 would sizzle and the captivating illusion would collapse. Instead of being immersed in music I would find myself propelled into preoccupation of the electronics.

Conclusion
Which tube is the winner for the Grado SR225? That depends on what kind of sound the listener is after. I think most people would prefer the Western Electric 408a vacuum tubes with the Little Dot I+. Both tubes do what they do well. However, with the Grado SR225 it is quite obvious that I prefer Sylvania GB-408A vacuum tubes to Western Electric 408a vacuum tubes. If I want clear dynamic solid-state sound I already have my Ray Samuels Emmeline XP-7. When I want to experience “liquid midrange” I will turn to the Sylvania GB-408A.

post #2 of 39
Im on a trip to la la land with my grados 225s right now. I use Mullard M8100. I feel they sound much like you Sylviana 408a tubes. An EXTREME Experience. Very "lively" Like them so much i cant get enough psytrance through them.
Damn i see many colors on the screen. What a good trip.
post #3 of 39
I love the Mullard M8100 with the I+, nice full tube sound with great vocals and bass. Will have to try the Sylvania 408A now that it sounds it's pretty promising.
post #4 of 39
The Moon HDAM should suit this little amplifier well I think.
post #5 of 39
Thread Starter 

MONTH TWO UPDATE

MONTH TWO UPDATE

February is already just around the corner. Tube rolling is taking me much longer than I had expected. The process takes so long since I have to clean tube pins, open the amplifier, adjust switches and jumpers, burn-in tubes, 1-hour amp cool down, and then repeat some of the steps again and again. Also I often switch back and forth between tubes which I have to allow time for the electrical charge to discharge. On top of that, I have been cleaning tube pins, burning-in, and shipping tubes for some of the other Head-fi members. Tube rolling is a vvveeeerrrry slow process.

Because of the slowness of this process, over the last two-month period I have only listened to a small number of my tubes. I have not yet gotten to any EF91 or EF92 tubes, since having to change jumpers for those tubes is time consuming and a pain. I will try to continue listening to more tubes over the next few months to add more tubes to the list after each time I finish listening to another batch.

Most of the listening from my impressions have been derived from the following setup:
Intel iMac – Fiber optic cable – Valab DAC – Canare Star-quad interconnects – Little Dot I+ (LT1364 op-amp) - Grado SR225

Tubes from the first two months of listening:


The plastic case works great for tube organizing.





Sylvania Gold Brand GB408A
Physical Description: “GB408A SYLVANIA GOLD BRAND” printed on tube / Box print adds a dash to tube model “GB-408A”

This is the tube that started all the magic with my Grado SR225. Thunder, lightning and ambience. You can read more comments about this tube above in the first post of the thread. After two months it remains the tube to beat. There is already plenty to read about above in my original post.

Little Dot I+ / Grado SR225 rating = 10





Western Electric 408A
Physical Description: These are available as upgrade tubes for $50 when you order the Little Dot I+ / Print on the tube is in bright yellow lettering

This tube also already has plenty to read about above in my original post. Please see uppermost first post of the thread.

Little Dot I+ / Grado SR225 rating = 3





Mullard EF95
Physical Description: Multiple small points protrude all the way around the spacing insulator / Square getter / Wide base and a vertical split down the middle on the “upside down T” on top of the cage assembly

Bass is perfect. Piercing highs of Grado SR225 are tamed. Well balanced and realistic. Some tubey sound to it, but not a lot. Music seems to come from in your head. Accurate and non-fatiguing. The compromise of this tube is some “air” and openness. However, ultimately gained is a very satisfying presentation with a feeling of fullness. Bass is strong. String instruments sound very full.

Little Dot I+ / Grado SR225 rating = 6





Mullard 6AK5 with large shield logo
Physical Description: Multiple small points protrude all the way around the spacing insulator / Square getter / Wide base and a vertical split down the middle on the “upside down T” on top of the cage assembly

Sounds pretty much like Mullard EF95 above except everything seems to be done just a tiny bit better. Although the sound seems much more liquid and much smoother.

Little Dot I+ / Grado SR225 rating = 7





Chinese 6JI
Physical Description: This is the stock tube that comes with the Little Dot I+

Vocals may have extreme recess in mid-range. Clear weightless highs create an over exaggerated open presence. Not a hint of piercing-ness with the Grado SR225. Bass level is equivalent to listening to speakers without a subwoofer, but enough bass to be satisfying. Sound is unnatural and unrealistic.

Little Dot I+ / Grado SR225 rating = 2





Raytheon 6AK5W
Physical Description: “RAYTHEON JRP5645/6AK5W” printed on tube in nice-looking orange / Box gives the impression that they may have been manufactured 1940’s or 1950’s but I am uncertain

Very clean, clear, and balanced. Decent amount of bass but it would not qualify as “thumping” bass. Offers some sound soundstage. Non-fatiguing. Only slightly tubey sounding. Does not create the illusion that you are part of the music.

Little Dot I+ / Grado SR225 rating = 5





Amperex 6AK5W
Physical Description: Box has two model numbers listed as “5654” and “6AK5W” / Someone posted that the “W” designates “improved” version of the 6AK5 but I do not have a non-“W” to compare and confirm “improved” sound

BASS! Equivalent to listening to speakers paired with a massive subwoofer in the room. Only about 90% of the tubey sound of the Sylvania Gold Brand 408A and about 90% of feeling you are becoming one with the music. This tradeoff is more than compensated for by the huge amount of bass produced. Bright, resonant, highs with pounding bass. Normally I listen at lower than average volumes. I don’t usually like to rock-out, but when listening with these tubes I cannot help it. I turn up the volume and play louder than usual. Fun, outrageous, and wild sound.

Little Dot I+ / Grado SR225 rating = 10





General Electric JAN 5654W
Physical Description: Lettering on tube is green print and white etching look.

Bass is deep and strong yet does not present a warm sound. A hint of brightness in the highs. Instead of letting you feel that you are part of the music, you feel detached. Mid range is clear but slightly recessed. Clean solid-state sound that is not very tubey. Can play loudly and maintains control.

Little Dot I+ / Grado SR225 rating = 4





Tung Sol 6AK5
Physical Description: Getter-compound is on the sides instead of on top. Heater glow is not visually obstructed. This is the prettiest tube of the bunch. Lettering on tube has white etching look.

Open sound stage with large ambiance in the realm of the Sylvania Gold Brand 408A. Male voices get a little lost in the music as if they were at a further distance. Warm full sound supported by full bass in the upper bass regions. Does not have low sub woofer type bass. With the Grado SR225 it is a little bit piercing. I would call it a more mellow, sterile version of the Sylvania Gold Brand 408A because of its less lively and less energized sound.

Little Dot I+ / Grado SR225 rating = 6
(I am still listening to this tube so the rating might change)
post #6 of 39
It'll be interesting to compare notes when I receive my 325i's next week.

With my DT770-250's, I didn't see a huge amount of difference between the Chinese 6JI's and the Sylvania Gold 408A's. Maybe a bit more warmth with the 408A's but not enough to make a big diff. The only noticeable diff was when I upped the gain, which added a bit more low end.
post #7 of 39
Thread Starter 
Quote:
Originally Posted by oldskoolboarder View Post
It'll be interesting to compare notes when I receive my 325i's next week.

With my DT770-250's, I didn't see a huge amount of difference between the Chinese 6JI's and the Sylvania Gold 408A's. Maybe a bit more warmth with the 408A's but not enough to make a big diff. The only noticeable diff was when I upped the gain, which added a bit more low end.
About five years ago I owned the Beyerdynamic DT-770 (600ohm). I really did not like it. Your Grado SR325i is the next model up from mine. It should take you to places that the Beyerdynamic DT-770 dreams of if you have a good source to play from.

Did you upgrade your op-amp from the stock one? It is a cheap $7 upgrade that I highly recommend.

post #8 of 39
Quote:
Originally Posted by oldskoolboarder View Post
It'll be interesting to compare notes when I receive my 325i's next week.

With my DT770-250's, I didn't see a huge amount of difference between the Chinese 6JI's and the Sylvania Gold 408A's. Maybe a bit more warmth with the 408A's but not enough to make a big diff. The only noticeable diff was when I upped the gain, which added a bit more low end.
With my DT-770/80 Pro's the switch from the 6JI's to the Sylvania Gold 408A's was like night and day. The amp originally only made the phones louder then when I was plugging them directly in my PC. No improvement in sound. The new tubes however opened the sound stage noticeably, tamed the bass some, smoothed out the highs and helped the mids. It was without a doubt the best bang for the buck improvement I could have made to my system. I just the other day added a DAC and I am WOWED. My Beyers don't even sound like the same cans. The DAC was double the price of the headphones but was more than double the improvement. I am happy enough now that I could stop even though we all know that is not likely.
post #9 of 39
Quote:
Originally Posted by hottyson View Post
About five years ago I owned the Beyerdynamic DT-770 (600ohm). I really did not like it. Your Grado SR325i is the next model up from mine. It should take you to places that the Beyerdynamic DT-770 dreams of if you have a good source to play from.

Did you upgrade your op-amp from the stock one? It is a cheap $7 upgrade that I highly recommend.

I might give a new op-amp a try sometime soon. Recommendations?
post #10 of 39
Thread Starter 
Quote:
Originally Posted by ArmAndHammer View Post
With my DT-770/80 Pro's the switch from the 6JI's to the Sylvania Gold 408A's was like night and day. The amp originally only made the phones louder then when I was plugging them directly in my PC. No improvement in sound. The new tubes however opened the sound stage noticeably, tamed the bass some, smoothed out the highs and helped the mids. It was without a doubt the best bang for the buck improvement I could have made to my system. I just the other day added a DAC and I am WOWED. My Beyers don't even sound like the same cans. The DAC was double the price of the headphones but was more than double the improvement. I am happy enough now that I could stop even though we all know that is not likely.

You too now have the Head-fi disease.
Welcome to Head-fi. Sorry about your wallet.

Now you have got me curious about the Beyerdynamic DT-770 (80ohms) headphone. I too have a new DAC. (Valab makes my face look like this ) The low impedance Beyerdynamic DT-770 (80ohms) are probably a completely different animal than the antique 600ohm version I once owned. Maybe I will have to give this combo a shot since I love a good closed headphone.

My poor wallet!

post #11 of 39
Hey man, thanks for your excellent and thorough reviews.

I have the grado sr225 too and I have been looking for a good amp. I want to try DIY projects like the CMoy and such, because I would enjoy DIMyself , however as I would be using an SS amplifier,and i have seen the Meier Arietta amp, but it is more expensive than this one, and as sound from tubes is different than from opamps I might actually go for this one. I do not like the idea of buying through ebay, but i hope that my first time (if i get this amp) will be satisfying. EDIT: Well I didn't write it totally correct, as this one is a hybrid between tubes and op-amps

Then are tubes expensive? I really do not want to buy any NOS nor anything. I am quite skeptical with that ultra-expensive products, and I would like to go for the cheap.

About following the instructions I read that you had to clean some parts, did they also send you the cleaning materials or you had to buy them apart?

Well will be following your comments about this combination.
post #12 of 39
Thread Starter 
Quote:
Originally Posted by Bullseye View Post
Then are tubes expensive? I really do not want to buy any NOS nor anything. I am quite skeptical with that ultra-expensive products, and I would like to go for the cheap.
Mullards vacuum tubes are fairly common and inexpensive in Europe. Some have reported fairly decent sound from Mullard tubes. If they work good enough for you and you are happy with that sound then you are only out maybe the equivalent of $15 US.

However, be forewarned. I have told myself and others that I would never venture into tubes because it would fuel an entirely new obsession. Then the Little Dot I+ arrived to the scene with a super low price. I figured that I could buy a few tubes with the money that I saved. On top of that, I convinced myself that since the Little Dot I+ is a hybrid amp, rolling just a pair of tubes would be a small venture compared to a quad, or trio of tubes right? I was so wrong! It didn't take long for me to get overly obsessed with tube rolling and I have spent an embarrassingly insane amount of money on vacuum tubes. Now, I am currently contemplating the purchase of a mutual conductance tube tester. This venture into the world of tubes is like falling for a hot woman. It is costing me a small fortune and I am deeply in love.

Quote:
Originally Posted by Bullseye View Post
About following the instructions I read that you had to clean some parts, did they also send you the cleaning materials or you had to buy them apart?
Yes, cleaner to remove the oxidation from the vacuum tube pins is one more expense. I use DeoxIT to clean my vacuum tube pins. Mine was purchased from Parts-Express.com but you might be better off buying it locally in Europe or perhaps some other equivalent European product.
post #13 of 39
Hey hottyson, any update coming soon?
post #14 of 39
Hey, I missed this thread the first time around. Great stuff. You'll are getting me trippy side going...... I, too have been on many fantastic journeys with head-fidelity. The kind where the message of the music just sinks in, to your soul.

I look forward to hearing more about the tuberolling.
post #15 of 39
Thread Starter 
Quote:
Originally Posted by Bullseye View Post
Hey hottyson, any update coming soon?
Lately, I haven't had the time to tube-roll. I have been swamped with teaching and preparing for my soon to be born daughter. Plus, the wife's hormones had been acting up and she did not like my audio gear spread out around all around the guest bedroom. So the tubes had to be put into boxes for the moment.

If I can get some listening in during spring break I will try for the next update in a few weeks. I am shooting for mid-April.

June 2nd is when my baby girl is due. I will be taking six weeks of paternity leave around that time. Hopefully that will allow me the time to listen to the rest of the tubes then and finish commenting/rating all of them.
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