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MiniMax for DT880/600 or K701

post #1 of 32
9/21/10 at 1:51pm
Thread Starter 

Hello.

You might remember me when I was asking what project should I do first. The general suggestion as to start with CMOY to learn some soldering skills. Then I had to give up on the idea since it looked like I am not going to have time for projects. Now I found that during this year I will have really a lot of free time (don't ask ) and since my budget was raised (was planning to buy commercial AMP) noticeably I thought I will check what could I go for in this price range if going DIY-way.

 

My budget was about $500 but then I found that all DIY AMPs from that price range require advanced knowledge so that is not an option. Then I spotted MiniMax, which looks to not be so complicated. It also is not very expensive since I can pay for it $220 at Beezar.

 

http://beezar.com/oscommerce2/catalog/product_info.php?cPath=37&products_id=125

 

Now I have few questions:

 - is MiniMax a good project for a beginner knowing that I have only theoretical knowledge BUT I can also spend really a lot of time on it (few week or months if neccesary)

 - in the linked MiniMax kit - would you suggest any changes to components so that the quality would be better? I could add up to $80 if it is worth it.

 - would MiniMax also work with very efficient headphones like Grado?

 - what commercial AMP can it compete with? Something of Musical Fidelity x-can v8p? (you can obviously refer to other AMPs either, I only want to get an idea of how 'good' it could be)

 

Thanks!

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post #2 of 32
9/21/10 at 1:58pm
Thread Starter 

http://www.diyforums.org/MiniMAX/MiniMAXpcb.php

 

I guess this link answers my question about the complexity (in other words how hard it would be to build) of the design. Seems pretty simple and I should be able to fit everything proprly.;)

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post #3 of 32
9/21/10 at 2:44pm
Quote:
Originally Posted by Professor00179 View Post

Now I have few questions:

 - is MiniMax a good project for a beginner knowing that I have only theoretical knowledge BUT I can also spend really a lot of time on it (few week or months if neccesary)

 - in the linked MiniMax kit - would you suggest any changes to components so that the quality would be better? I could add up to $80 if it is worth it.

 - would MiniMax also work with very efficient headphones like Grado?

 - what commercial AMP can it compete with? Something of Musical Fidelity x-can v8p? (you can obviously refer to other AMPs either, I only want to get an idea of how 'good' it could be)

 

Thanks!


- It is a good project for a beginner (it was my first after all): it's low voltage, the casing is already done if you buy the kit and there is very little wiring to do. However, I doubt you'll spend a "few weeks or months", since I was able to build it in an afternoon and evening.

- When I bought the kit from Beezar, he offered Black Gate capacitors for an upgrade, which I bought. I don't know if he still does, or if they do improve the sound quality. For reference, out of my 3 DIY amps, it's my least favorite (still sounds good though).

-  They work with Grados. It's an hybrid, and AFAIK, the only amps which have trouble with low impedance headphones are OTL.

- Can't compare it with commercial amps, but, as I said, it is my least favorite of my DIY amps.

 

If your budget is $500, you can also look at the Bottlehead S.E.X. kit. I haven't listened to it, but Bottlehead makes amazing instructions and they consider it a "Skill level 1" kit. They're also upgrade kits for when the soldering bug hits.

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post #4 of 32
9/21/10 at 3:50pm
Thread Starter 

Thank you for a fast reply. I have found used Whiplash MiniMax and now I am negotiating the price etc. Seems that I will probably buy the already-built MiniMax, which might be the best solution in my case. It is pretty sad that I will not do the project on my own (would help in the future) but I think it will be safer to go with the pre-built unit. I have never had any contact with proper headphone AMP anyway. However, it is very likely that I will try to do some mods like changing parts to better ones so nothing lost.;)

 

Also I am not very convinced about the price of $300 but I guess will see.

 

As for the Bottlehead - I had a look at it. Well.. while it fits into my budget I would much rather get something cheaper for first DIY project. That is an option though so thanks for the suggestion.

 

I have some questions related to MiniMax. Is that sufficient for DT880/600? You actually have DT770/600 and K601 which are supposed to be very inefficient either so you might help me with this. Also - what is the sound siganture of this AMP? I am especially 'interested' in airy soundstage with good depth and smoothed highs. Would MiniMax meet those requirements? My assumption is 'yes'.

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post #5 of 32
9/21/10 at 4:22pm

It has no problem running any of my headphones, even the HE-5LE. As for the sound signature, I find it neutral, but ... I'm having trouble finding words for it. My impression when listening to Harmonium would be that it is "gray", it lacks musicality. It never gives me the illusion of a wide soundstage, I can hear the notes clearly, but they remain dry. Compared to my Castanet, it lacks its dynamics, its extension, the imaging and the "richness" of the notes (those single high notes on "Depuis l'automne" sound fantastic, as well as the low bass).

 

For a $220 DIY kit, I believe it's a great mean of learning the hobby and getting a decent amp in the process; for a $300 commercial amp, I believe there's probably better ones out there (even if I don't know them).

 

By the way, I ha written a comapraison between my three amps (that I need to update with my new headphones) here: http://www.head-fi.org/forum/thread/503622/showdown-3-diy-tube-and-hybrid-amps-millett-hybrid-minimax-bottlehead-speedball-crack-hagerman-castanet#post_6927298


Edited by WyldRage - 9/21/10 at 4:25pm
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post #6 of 32
9/21/10 at 10:36pm
Thread Starter 

ok. Thank you very much. Now still talking to head-fier, who agreed to ship his MiniMax to me at $325. The price is not a bargain but I suppose it will sound much better than the 'stock' Whiplash Audio unit after I change some components to ones of better quality. He also offers (form what I understanded) 3 sets of tubes so that is another strong point and with some warm and nice tubes I might feel better musicality... hopefully. I have never expected AMPs to be very musical but that said DT880 and K701 are not very warm and nice sounding either (one of reasons why I am looking for a tube AMP). Guess will see how it goes. I can always sell it at minimal lose. Thanks.

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post #7 of 32
9/21/10 at 11:26pm

What better quality parts are you going to change? I don't mistaken, the Whiplash's Minimax has some BlackGate NX caps in there already. I doubt you would get a 'much better' sound.

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post #8 of 32
9/22/10 at 4:16am
Quote:
Originally Posted by Lil' Knight View Post

What better quality parts are you going to change? I don't mistaken, the Whiplash's Minimax has some BlackGate NX caps in there already. I doubt you would get a 'much better' sound.


Actually, it depends on the vintage of Whiplash as to whether it has Black Gates.  The earliest run of Whiplash MiniMAXes had Muse ES output caps (as with the Beezar kit) and only sold for $400.  The later and present Whiplash MiniMAXes have the BG's and sell for $450, I believe.  One of the newer ones may be the only way you can get BG's, because they no longer exist in any vendor's inventory.

 

Lil' Knight is correct that the BG's are essentially the only upgrade that will make a difference.  The MiniMAX kits already have the best parts selection available, except for that.  You can tweak one for low-impedance performance by substituting Muse FG's at the output, but those are generally less regarded than the Muse ES caps, which are standard.
 

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post #9 of 32
9/22/10 at 4:23am
All of the whiplash builds use some of the best part compliments available for the miniMAX. Beyond removing the output resistor and going with a straight jumper, I see nothing that could arguably enhance it's performance any more. I would not even suggest that, I would just leave it alone.

I know this as I have one. I have opened it up. The only thing I did was to rebias the buffer. Unless the previous owner went medieval on it, the stock configuration is excellent. One of the best.

In any case, you are in for a sonic treat. Be sure to try out the different tubes. Your headphones are polar opposites. The k701 will be better with 12FK6 and the DT880 will be better with 12AE6, or split the difference and put a set of 12FM6 in the amp and be done with it. See Beezar if you need additional tubes.
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post #10 of 32
9/22/10 at 7:31am
Thread Starter 

Well the version of MiniMax I am getting already has Black Gates so you are right that there is not much I could do about that. My assumption was that higher quality parts would considerably improve the SQ but seems like it is not the case. If I am right the 'synergy' of components is more important, isn't it? Tube-rolling therefore is the only way that I will use to change the sound. At least I will have the AMP that works without any problems (if comes in described quality) and does not require no further work on it. Still some part of me screams that DIY would be good since in the future I could build some better AMPs but brains says to go with Whiplash MiniMax and do not worry whether it will or will not work.

 

I have a different question now. Since i will (sure for 90%) go with pre-build MiniMax and I still want to do some project I could build a DAC. Do you think that DACs are good for beginners or there are too many small parts? This is at least what i heard about Gamma2 and few other projects. Is there any pretty simple DAC that would nicely compliment MiniMax? There is no strict budget for that project since I will start it later. I guess I would like to fit in $200-$400 with the whole DAC kit including casing. Thought about Gamma2 but like I said I have read somewhere that it is not an easy project for a start. So the perfect DAC would be quite easy to build (bearing in mind I can buy a spare PCB and some parts in case I destroy something or just to practise), fit in the suggested price range and should not be too big (something of MiniMax size). Is there anything I could be interested by or it is yet to be designed?" class="bbcode_smiley" height="" src="http://files.head-fi.org/images/smilies//wink.gif" title=";)" width="" />

 

Thanks for great help so far!


Edited by Professor00179 - 9/22/10 at 7:33am
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post #11 of 32
9/22/10 at 10:19am

The only further work I could image is re-biasing after a couple months using or swapping tubes. My MiniMax didn't fluctuate a lot though.

 

The Gamma-2 is surely a great DAC, just go for it if you feel confident enough. The casing work is almost zero because you can get the pre-punched panels from AMB.

Or you can try the GrubDAC as first project. Should give you some SMD practice before handling the Gamma-2.

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post #12 of 32
9/22/10 at 10:40am

I have a Gamma2, and it took me quite a while to make it work, but it was worth it. Since you are a beginner however, I must warn you that Surface Mounted Devices are very difficult to solder. I agree with Lil' Knight, try the GrubDAC first instead.

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post #13 of 32
9/22/10 at 12:09pm

This is a great tutorial on SMD soldering: http://store.curiousinventor.com/guides/Surface_Mount_Soldering/101/

 

You will need a fine tipped iron, tweezers, flux pen, solder wick,and the 10X loupe to be able to do the job.  The loupe is important to be able to examine your joints for solder bridges, etc which is usually the most common problem.

 

if you want to start out with a cheaper dac, try the Grub dac, to get better at SMD before you tackle a Y1 or Y2. 

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post #14 of 32
9/22/10 at 1:17pm
Thread Starter 

I guess I will have to then think twice before spending money for Gamma2 since I do not feel very confident with soldering. Actually I have never done it.:P

 

I could create GruboDAC but it would not make a lot of sense in my case. I am doing DIY because it helps to learn more but I would also like to see that DIY helps me to save money while building up my headphone system. It is often said that DIY is a hobby first and savings are the last reason to go for it. I am aware of that and would definitely enjoy DIY as a hobby but only in case if it not costed more than commercial products. I mean if I could do DIY projects spending about the same amount of money as I would when buying commercial products of similar quality it would be fine with me. It gets a bit more complicated when it comes to building GrubDAC and Gamma2 though. Building them two (assuming GrubDAC would be a practise) I would spend quite a lot of money and I could buy commercial products for it and the would not need to worry about my soldering skills - it is highly possible that I may spend money for Gamma2 or GrubDAC and then not be able to build it. It was not an issue with MiniMax which did not require no SMD soldering so I was convinced I would be able to do this. Similarly in this case - if I was sure I can do it I would go for Gamma2.

 

Hope you understand something from that complicated explanation above. To summarise I would say: I would go with Gamma2 if I was sure I will be able to build it. I will probably not go for Gamma2 because it would (most likely) need some practise with e.g. GrubDAC and by adding cost of GrubDAC + Gamma2 I would have enough money for a commercial product of similar SQ to Gamma2 but I would not have to worry about my soldering skills. Hope you get what I mean.

 

For now I will do one thing - read about SMD soldering and see if I could do this without practising with GrubDAC. I would NOT like to practise with GrubDAc since it would take money, time and in the end I would end up with Gamma2 or Gamma1 so that GrubDAc would not be in use anyway. Just to make sure - am I right thinking that ANY DAC would require SMB soldering? I guess it is soldering of chips, right?

 

Also - what are other options than Gamma2 and Gamma1? Preferably similar or better sound quality than y2.

 

EDIT: MrSlim - thank you for the link to the vide. Unfortunately I can not watch it now (stupid, british broadband), but will do it tomorrow and then I will see if SMD soldering is so horrible.


Edited by Professor00179 - 9/22/10 at 1:26pm
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post #15 of 32
9/22/10 at 3:11pm
Thread Starter 

Hmm... I am asking a lot of questions but... have one more now. This time it comes back to the topic and MiniMax.

 

I have read about tubes with different gain that you can get from Beezar (and I am buying it with all 3 sets of tubes) and just wonder if I could use tubes different than that. I know there is noly one TYPE of tubes that could be used, but is it really limited just to 3 different tubes that will work with MiniMax? I would like to find e.g. some good NOS tubes that would open the soundstage etc. Could I buy such tubes e.g. from eBay and use it with Minimax or only those 3 from Beezar would work?

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