[boschtb]

I am considering buying a Super Mini IV, as I really like the form factor. I love the sound of my Hornet (unmodified), but tend to like a variety of sounds, so I am not wed to the type of sound.

Dr. Xin's website lists three basic options for the Mini configuration -- I know there are many more, but I don't know anything about opamps, buffers, etc., so I'm sticking to the basics -- and I would like to know the general differences between the three. Here they are:

XIN SuperMini-IV (AD8397 chipset default)

Solid Tube Chipset (2.5V-5.5V, don't use 12V!, buffer not required)

ST-WV + LMH6643 Chipset (2.4V - 12V)

For example, what is the solid tube chipset, how does it change the sound and what do things like "don't use 12V" (does this mean don't charge, don't run off of AC, etc?) and no buffer required mean? Same questions for the other option.

Can anyone help?

Thanks much.

 

[aluren]

Yeah I'm interested in knowing too. Is there a book out there or something where we can read and say 'Oh, so that AD chip will make the sound to be like ____."

 

[Asr]

I can't speak for other AD op-amps, but the AD8397 livens up presentation and boosts attack and overall energy. It extends the highs a bit and lets the bass slam out with a full impact.

 

[crazychimp132]

http://www.fixup.net/products/iv/miniivops.htm
Here are the tests for the different chipsets. AD8397 and ST-WV seem to be quite similar in sound, while ST has noticeably higher THD and IMD, meaning higher levels of distortion, or tube-like sound. I'm just showing these tests, though, I have not heard any of these on an actual SuperMini-IV. I have AD8397 and ST-WV for my SuperMini-III, however, and while similar, AD8397 provides more impact, ST-WV drains battery much less, gives a kind of smoother, deep sound.

 

[optics99]

The AD8397 runs well at 3v and up thus extends its current-hungry battery life. More current draw...better sound quality. At least the gurus say this.

I'm waiting four weeks for my SM-IV and have acquired pairs of AD8397, AD8620, LMH6648, OP2134 and OP275(As default) with bu634s where needed. They're like interchangeabe lenses.

I expect to stay with the OP275 for several weeks to a month as it delivers the best benchmarks. Especially in bass where it dominates the bench results. Indeed, the benchmarks are almost too good to be true but...there are the RMAA pics to validate Xin's audio design achievements! VERY low noise and very portable. All one needs now is a flash iPod with 20 Gigs (To permit lossless listening with no hard drive intervention).

The new Sanyo hi-capacity NIMH AAA batteries permit the hi-current op amps to obtain a much better between-charge life.

 

[MrYman]

this might answer some questions:
http://www.fixup.net/talk/topic.asp?...60&whichpage=5

Quote:

After a few rounds of op rolling, I'd say the op for 3rd has significant influence on sound, even though this op have a gain of one without voltage swing (theoretically, but in real world, who knows). This op is critical as it's working under the worest situation - unity gain that most op's don't like. So far, I have tried quite a few dual op's and here report their sonic signatures in this specific application for your reference. 1. LMH6643. This op is very stable in 3rd and 4th. It's relatively warm and smooth and has great soundstage. However, the bass is not as clean and powerful as op275. If an op has slightly better bass definition than LMH6643 would be ideal. 2. JRC NE5532. This op provide a clean and correct sound. Bass is punchy and mid is neutral. High is very good as well. There's nothing special about it. 3. S NE5532N made in 1987. This op has a cleaner presentation than JRC NE5532. Soundstage is deep and image is super. The bass is fast and clear, less punchy than JRC5532. 4. OP275. This op has the best detail and biggest soundstage. The bass is phenominal, very powerful and articulate. However, slightly agressive compared to LMH6643. It has the best RMAA benchmark may say something about it. 5. OPA2604 has a warm yet neutral presentation. Very good image and soundstage, less relaxing than LMH6643. 6. OPA2134 is the most relaxing compared to other op's used in 3rd. Soundstage is not as deep as other op's. 7. JRC 14558. This op is very good, as relaxing as opA2134 yet better in high and bass. On par with LMH6643 overall and has better bass definition and more silver-like high. This op reminds me that high-speed op's may not be the best in audio, especially in 3rd. 14558 is very slow compared to others, yet very musical and nothing short of detail and impact and other hi-fi elements. All in all, op's sound varies in different applications. The impression may change when op's are used in left or right channel with gain >3. So far, I haven't found an op that outperformed others in a significant margin, and I have yet to find the "best" to my favor.

 

[boschtb]

Thanks everyone for the responses so far. They have been very helpful, albeit a little advanced for my first thoughts of buying an amp that allows op-amp rolling. Can anyone answer the more basic questions in my first post to get me started?

Thanks.

 

[redrich2000]

Quote:

Originally Posted by boschtb Thanks everyone for the responses so far. They have been very helpful, albeit a little advanced for my first thoughts of buying an amp that allows op-amp rolling. Can anyone answer the more basic questions in my first post to get me started? Thanks.

You should check out Xin's website fixup.net it explains most of this stuff and there's a forum there too. I have a supermini3 with both the stock op amp and the Solid Tube op amp. I'm not total audio head like most here. To my ears the Solid Tube sounded maybe a fraction smoother but its a very sublte difference. But it improves battery life by a factor of 5 which was a winner for me.

Unless you really want to get into playing with your amps insides, you don't really need to know about buffers and such.

Don't use 12v means you can't run it off an AC adapter unless it has a voltage regulator you can set to below 5.5. You can get AC adapters that have multiple voltage settings, others just have one. You also wouldn't be able to use a special external battery pack which some of the purests like.

Hope that helps.

 

[boschtb]

Very Very helpful. Thanks much. Also, I posted on fixup.net yesterday and already got one response. Thanks again.

 

[boschtb]

Can someone with the Mini-IV measure the distance between the Audio-In and the Headphone out jacks. I am trying to figure out if I could use it with my Audio Line Out Silk Doc and my A900LTDs, or if I would not have enough space.

Thanks,

Tom

 

[sxr71]

Quote:

Originally Posted by redrich2000 You should check out Xin's website fixup.net it explains most of this stuff and there's a forum there too. I have a supermini3 with both the stock op amp and the Solid Tube op amp. I'm not total audio head like most here. To my ears the Solid Tube sounded maybe a fraction smoother but its a very sublte difference. But it improves battery life by a factor of 5 which was a winner for me. Unless you really want to get into playing with your amps insides, you don't really need to know about buffers and such. Don't use 12v means you can't run it off an AC adapter unless it has a voltage regulator you can set to below 5.5. You can get AC adapters that have multiple voltage settings, others just have one. You also wouldn't be able to use a special external battery pack which some of the purests like. Hope that helps.

Well you could run external battery power if you're careful like maybe with 4 1.2v NiMH batteries, but certainly no 9v batteries. You just really have to know the limits of each op-amp and then make sure you don't burn it out.