AUDIOLAB 8000A Modification

Dear WINDWSS,

I recently bought a 2nd hand 8000s.

I found the op-amp is a 2134...

Can I replace it with a better op-amp like LM4562 ?

In 8000s, which part does the op-amp used for ?
Pre-amp ? Amplification stage for the power output ?

Please advise ....

as long as the pin location is the same as OPA 2134 and the voltage supply is >15Vpeak (or >30v rail to rail) should be ok to be use.

I can't advise u on the sound of LM 4562 as i do not have this chip to test on.... sorry...

i only had test on 627AP, opa 227, opa 2132, TL 082, AD 825, opa 827, OPA 2604 only....

Hi WINDWSS,

Do the volume level playing affect the "run-in" time?



Bryan

Hi Bryan,

Till date what type of component u had change?
Can share with us the sound changes of ech component?

If u r running in the component such as capacitor, resistor & IC, i don't think the volume level will make any obvious differences excpet if u wre run in a speaker than volume leve and type of song/music may play more roll.

fro running in component i personally feel that the discrete run in method may be more effective than continuos run in. E.g (1hr+1hr+1hr )--> total 3hrs but with interval maybe more effective than continous 3hour especially for capacitor. As during interval, the equipment is off and the cap can full discharge then when on again it will charge from zero to full.

Dear WINDWSS,

Have change the default OPA to 627BP x 2 and changed 470uf cap x 5pcs., the resolution improved a lot!!, now just waiting for 100uf BG cap.  and some rifa and ero mpk caps.

I cannot find a good cap to replace default Elna 10000uf and want to use your method  " pararell a 0.47uf/50v blackgate nx-hi-q with 10000uf Elna Cap"? but can you teach me how to pararell?  need to buy 2 x 0.47uf cap?


Sugargar

Finally I have changed the 2134a op-amp to LM4562... for my 8000s

Also I have changed 2x134a op-amp to LME49710... for my 8000p

This is my bi-amp set-up....

->8000s->High frequency->Speaker
->8000s->8000p->Low frequency->Speaker



Both op-amp is from national semiconductor, they have similar audio characteristics....

http://www.national.com/pf/LM/LM4562.html
http://www.national.com/pf/LM/LME49710.html

Dear Sugargar,

yes, u need 2pcs of 0.47nx-hi Q since u got 2 pcs 10000uf big tank.
Then u will get smoother sound.

Dear michael,

Can you share with us the sound differences between LM and BB OPA?

What's the cost of LM4562?

Hi WINDWSS,

I have changed all ecap to black gate (except those in the phono circuit), changed the ELNA reservoir to Jensen, change the OP AMP from TL072 to 827.

The overall performance is wider in the soundstage, the vocals is more dominant, the sound is more 3 dimensional now.... In the sense of resolution, I didn't find big improvement...

The sound is now warmer and smoother, may be it's owing to the effect of the black gate. But black gate do need time to run in, everytime I found warmer and thicker sound from this 8000A when it's played for over 1 hrs.


Bryan

the warm vocal shld be due to the jensen resevoir, you use jensed gold 2pole or black 4pole?

blackgate will make the system more musical and transparent with good bass the resolution will increase a bit. But this cap really take time to run in!!!

If u 12 increase somemore on resolution then need to replace the evox film cap, the risk is it may reduce the warm/thickness so not necessary do that. But the 0.1uf evok film cap in between the 2 reservoir must be change (this cap really play role).

your 827 is AD 827 or BB OPA 827?

Hi WINDWSS,

My Jensen reservoir is black 4 poles, I remember you said the golden 2 poles is better, right?

The opa is AD827. I think I would prefer the sound's warmness, don't wanna use it for exchanging higher resolution.

As I remember, now you use the 8000A as the power amp only, you just connect ur preamp to the "power in" of the 8000A?


Bryan

jensen gold 2 pole have warmer sound but softer bass... those vocal lover will prefer the gold.

I'm using AD825sound shld be similar to your AD827.

without internal separation will use the preamp in (but my tube preamp volume need to raise till 3'o clock"

if use internal separation then use power in, then with 9 o'clock volum is very loud already but my old old version 8000A have problem where the preamp will become very microphonic..any knock/vibration will transfer from preamp to the speaker (in brief my tube preamp become like a microphone)...

so what i do is use the "preamp in" without internal separation but i change the internal resistor value so that my tube preamp don't need to raise till 3'o clock.....

i personally feel that 8000A's preamp section is better than its power section. Since u had modify so much on 8000A(especially preamp section), u shall use it as a preamp and look for a nice power amp in future upgrade.

If u 12 have soem tube sound just DIY a good tube buffer. the cost to DIY a tube buffer is much lower than DIY atube preamp as u do not need a volume control on buffer.

A lot people tends to select 8000P as power amp when use 8000A as pream... but i'm not so keen on this as i feel that there are plenty of power amp outside can do better job than 8000P.

E.g quad 606 power amp, creek A 52 SE and so on.

i have a friend is using 8000A with Quad 606 and a 5687 tube buffer, another 1 using creek A52SE (he sold his 8000P-mod with blackgate after tested on A52SE)...

Hi WINDWSS,

QUAD 606 is a good power amp? Do you think it can push 3/5A speakers? Do you know the approximate 2nd hand price?


Bryan

Quad 606 is 140W/channel into 8 ohm...

it can push ProAc 1sc (84dB) easily... so i can't see any problem for it to push 3/5A.

606's sound is more refine than 8000P imo, for solid stte amp consider nice vocal..very good control....

2nd hand price ~hkd4500

Hi WINDWSS,

Is it easy to find a good condition QUAD 606 Mk2? Any channel you know? You can PM me.

For matching a tube pre amp and a solid state power amp, what figure we have to be awared?


Thanks
Bryan

For 2nd amp u may look at teh shop of website... HK shld have a lot place to get 2nd part....since i'm not in HK i'm not so familiar...

my friend buy in from singapore (through echoloff web)

for matching--> input impedance of the power amp.....u need to plug in the tube preamp into the poweram then only can know it is really matching or not.....

Hi WINDWSS,

Don't know u're not staying in HK!

BTW, do you do any A/B test between 8000A/8000P & 8000A/QUAD 606? If yes, what's ur detail comments? Since I plan to upgrade my speakers to Focus Audio FS68SE, it's sensitivity is only 85db.... some people said that 8000P can only drive FOCUS AUDIO FS68SE well if the listening area is below 100 sqft. I guess a UK made power amp (QUAD 606) which can offer 140W per channel (8 ohm), it can then push many speakers, but don't know what's it's output current (this is an important factor for pushing low sensitivity speakers).

I wanna buy a versatile UK made power amp for long term use, don't wanna change equipment frequently.... I wonder if QUAD is one of the best choice...


Thanks
Bryan

Hi WINDWSS,

More questions about the matching of 8000A with QUAD 606...

From this 2 unit's spec, the output impedence of 8000A is 600 ohms and the input impedence of 606 is 20K ohms. Do they match without problem?

What's the meaning of "inverted phase"? People said that QUAD 606 is "inverted phase" but 8000A is non-inverting. Can they be matched as a couple?


Thanks
Bryan

Hi WINDWSS,

Any experience with QUAD 909? How would it compare with 606?

For QUAD 606 Mk2, it's using EI transformer or toroidal transformer?



Thanks
Bryan

If not mistaken, 606 got several version, older version using EI transformer, newer version use toroidal transformer..

I believe the inverting & non inverting u r mentioning is refer to the inverting signal & non inverting signal. The iC/opa can act as diffrential amplifier or comparator. Some circuit will use non-iverting signal and the phase of input signal and otput signal after amplification is at same phase.

Inverting circuit is opposite, input signal is 180 degree different with output signal.

So the inerting & non-inverting is the method they use to amplify the signal only.... u can search though the the internet on "voltage comparator" & differential amplifier" to understand more on how the IC(OPA and so on) working with the signal..

so far no problem on matching 8000A with quad 606. But to match tube preamp with Quad 606 you really need to test it out.

E.g. the tube preamp i make can use with 8000A with no/un-audible hum but when use with Quad 606 the hum is obvious.

No exp in 909, believe that 909 shld be a better 1 but the 2nd price shld be much higher.

Hi WINDWSS,

I bought the QUAD 606!

For my first impression, 606 give me a deeper bass and thicker sound when compared with single 8000A. I think I have more choices of speakers now.

Hope that I can explore more from this unit.


Bryan

Wow.. u really fast action, how much u bought the 606?

606 have much better control on the bass and sound comfortable, even at very low volume, it can still give nice detail. Not like audiolab need to raise to certain level then only the real sound coming out.

And u can feel that Quad 606 play music easily, audiolab is like struggling... no choice the pwer ration is a lot difference. For moderate cost 2nd solid state amp, Quad is 1 of the good choice. Another choice is Restek tensor (200w) but more expensive and it maybe not as warm as quad which shld be pair with tube preamp.


If u intent to keep the 8000A as pream, later upgrade is to DIY or get a tube buffer to place in between your CDP & 8000A... then u will have tube feel, better resolution, sweet and powerful system.

In case u r DIY/getting any tube buffer here's some sharing, it is only my personal view.

1) 5687 tube --> very good resolution, tube feeling is moderate
2) 5670 /2C51 --> more tube feel but less resolution
2) 12AU7--> very nice tube feeling, HF & mid is really sweet but bass seems a bit less.

In case u DIY a tube buffer, my advise is that the cathode bias cap must use at least blackgate std better if can afford N series. For signal coupling, moderate cost cap is mundorf Zn, higher is jensen cu, my ultimate choice is Vcap teflon..

In fact  i had DIY a 5687 tube preamp for my friend, when use it to the quad, it actually give better resolution, sweeter sound compare to 8000A but bass not so strong. Anyway the 5687 tube preamp have obvious hum when use with Quad 606 which i need to solve this problem. So temporary he use this tube preamp as a buffer....

Hi WINDWSS,

My 606 cost $5500... I can't find one from those c-hing on the internet and I bought it from a 2nd hand Hifi shop. That's why it's rather expensive.... I think mines is the later model as the top edge of the chasis is NOT right angled one.

Do the market has the ready made "tube buffer"? What's the average price? I'm really not confident to make one for myself, any channel to get one?


Thanks
Bryan

Hi all,

Finally completed my 8000S upgrade project, changed the following things:

Cap >470uf (Nichicon KZ)
Cap  100uf (Blackgate FK) (Blackgate Non-Polar)
Cap <100uf (Blackgate PK)
Cap <1uf (Rifa, Evox MPK)
10000uf Cap (Jensen 63V)
OPA > (627BP x 2)


The quality is excellent, sound more clear, natural  and musical a lot.

換埋火牛

ALC,

Change power transformer??
Very expensive oh.......

Bryan,

Just ask people here DIY 1 for u ~ HK1000 can be done for a single tube 5687 buffer, since tube buffer don need volume pot.

Hi Autumnleafcat,

I think I met you before... I'm the owner of "Jack", the Cream British shorthair...


Bryan

Really, the world is so small ...

Hi WINDWSS,

What do you think of the below 5687 tube buffer?

http://cgi.ebay.com/Core-Audio-6BC4-tube-buffer-5670-cca-6sn7-5687-el34-6l6_W0QQitemZ300267943841QQihZ020QQcategoryZ12050QQtcZphotoQQcmdZViewItemQQ_trksidZp1742.m153.l1262


Bryan

6BC4 is single channel, it is diffrent pin from 5687 so can't plug in straight away.

No schematic and never try it so only can bse on picture to comment.

1) the casing look nice...
2) it use toroidal transformer--> if this toroidal trans is not special made/of very good quality it may even worse sound than EI transformer. Tube stuffs easier to get good sound from EI trans unless the toroidal/R core type is speciall made for tube...
3) it use solid state retifier--> don't expect the imaging & sound tage to be very good, i prefer tube rectifier which give better imaging, sound stage...
4) the ecap is so so...u may need to upgrade later
5) PIO is warm sound--> but it depend on build quality
6) Iron case not as good as aluminium case
7) pcb is not as good sound as direct connection...
6) If u can DIY, with usd250 u can build a better 1...


i wish to post u some schematic of 5687 but this few days my server got some problem... if wisg fats response can just email to me sswong@healthtronics.com.my

so i guess the sound of this 6bc4 buffer is warm sound with tube feel but lack of sound stage & imaging, it may sound like compact to the centre.

Anyway i might be wrong....

Bryan,

Here's some schematic

the cathode follower is no gain buffer.

the other is tube preamp but u can made them as buffer, just replace the volume pot with 2 resistor (47k -from input to grid & 10k to ground)

Hi WINDWSS,

Thanks for your info.

The schematic in the pdf file is the one u DIY for your friend? Do you know any high hand in HK which can DIY these stuff? I really have no idea...


Bryan

Hi bryankeeper,

Would you share with us the photo of your cream boy?

autumnleafcat.

Hi bryan,

The 5687 i mad efor friend is simlar to this attchmnet AN-M7, it is a preamp which have gain and it use less film cap thus easier to obtain decent sound with low cost.

the 5687 cathode follower is no gain.

Modi sir in hififever had a very good diy an-m7 5687 preamp, so u can actually ask him to DIY 1 for u but without the volume pot (save cost) as u use it as buffer, latter u can juat add a volume pot to use it as preamp if u like.


For transformer if u got budget can use good 1 like SAC silk (~hkd600+) or like me temporary use a cheap 1 ~hkd100+... the cap u can use a good 1 like jensen cu, intead of 0.1uf, i prefer to use 0.22 or 0.33, jensen cap now got offer in below web. http://www.partsconnexion.com/catalog/CapacitorsFilm.html

the aluminium casing , here got 1 source, the AL314 is big enough for tube buffer or preamp
http://www.vt4c.com/shop/program/main.php?cat_id=1032&group_id=2

http://www.partsconnexion.com/catalog/CapacitorsFilm.html


cathode bias cap can use blackgate N series 220uf/6.3v of standard 220uf/16v depend on your budget.

If ur budget is tight, i will suggest u to spend on the good cap & resistor (so that don't need to upgrade anymore on this)and use old casing (frm VCD/DVD player) & cheap transformer, next ugrade only change to good
transformer and nice casing...

Other than Modi, i believe autumleavecat and alfcat can also DIY this simple buffer.... i saw somebody selling this 5687 preamp here but seems those who buy from him have bad comment on his after sale service and his preamp claim to have hum...

another alternative is that u just get your hand in for your 1st DIY project it is not so difficult. there are a lot infor from website below:

1) www.diyparadise.com
2) http://yunwt.u111.net/2wenzai_pre/pre11.htm

Hi Autumnleafcat,

I'll post some jack's photo later...

i mix "pro plan" + "innova evo" for jack but he eats little only.... he's thinner than before. I have no choice but feed him "Royal Canin 38" now, now he can eat 3/4 cup! much better than before, don't know vera will blame me or not....



Bryan

Hi WINDWSS,

Thanks a lot for your detail information!

I have sent an message to Modi sir already, don't know he's interested to help or not.

Anyway, thanks for all your great help!



Bryan

Hi bryankeeper,

If your cream boy's diet is allright, then everything would be allright.

http://www.arcdb.ws

have a look !

http://www.arcdb.ws/LS22/LS22.html

reasonably simple yet good performance preamp ...

Hi WINDWSS,

If adding the tube buffer, what role do the 8000A play in my system? Is it still significant?



Thanks
Bryan

8000A still act as preamp..... but u will have some tube sound/feeling, and slightly better clearity.....and smoother vocal.

U will able to hear the different!!!

Ha go and borrow the marrantz M7 form Alcat as use as tube buffer to test out : )

Hi WINDWSS,

Are all tube preamp can act as tube buffer too? If so, is it more versatile to have a tube preamp rather than tube buffer? Tube preamp can act as tube buffer but tube buffer cannot act as preamp....

Did u heard of a preamp Cunningham CX-301A?



Bryan

u are right! all tube preamp can be use as tube buffer.

The difference is that tube buffer without volume pot as a very good volume pot is can be quite expensive.

Yes, if your budget is ok, then get a tube preamp let u have more option to play with but ensure the volume pot in your preamp is not the loudsy 1... minimum is Alps, better is those step type. for step type u can save cost by using good resistor at the volume level u commonly use, the not commonly use level just use cheap resistor.


u can use tube buffer as preamp if your CDP have volume control...

Different tube have different sound, different brand also have different sound.... i'm quite new on tube stuffs does only have experience in popular tube like 2c51, 396A, 12AU7, 12AX7, 5687, 6N3.... some is more tube feel, some is more detail...depend on your taste...

Most important is that u must listen to it and judge whether u like it or not? As the sound i like may not be the sound u like....

Dear all,

I'm going to try bi-amp by adding Audiolab 8000P but have the following questions:

1) In watching movie, I'm using Onkyo 703>> AVbypass (Audiolab 8000s) >> Linn Katan Bookshelf speaker.  Can I add a 8000P to bi-amp push the speaker and still can function well on the AVbypass?

2) As my Audiolab 8000S has heavily moded with Jensen 10000uf cap etc, do I need to mod the 8000P too with same brands of caps so as to make the sound more match?

3) Any comment on the quality of sound by using Bi-amping to push the speakers compared with using single intergrated amp to push?

4) Anyone have experience in modding 8000P? can share some photos on the PCB, parts list or experience about modding it?


Sugargar

For item 2) You not neccessary to use jensen, it is depend on your system now, if your system now is already too warm & sweet with very soft bass then not advise to use jensen again on power amp.  For matching we need to achieve the balance... when our cdp is very analytical, then we will try to use warmer amp to achieve the balance and so on....

for item 4) nothing much to change

there only only a few e-cap can be change, then the OPA, then 4pcs of big tank 10000uf if you wish... anyway a mod 8000P (big tank is not moded) seems not as good as a creek 52SE & Quad 606...

Hi WINDWSS,

I've just got an Audiolab 8000P from my friend and I found that there are 2 x OPA134P inside, want to know which OPA can reaplace the origional one, e.g 627BP or AD797? and suggestion?

Sugargar

134 can be repalce by OPA627.
But my advise is spend to replace all the e-cap to blackgate 1st then bypass each big tank(10,000uf) with NX hi-q 0.47uf.
OPA627 is expensive and effect is not so much compare to the changes of E-cap.

then change the rectifier diode to shocky diode or ultrafast diode (farnell got some diode on clear stock price), u in which country??

Actually, I've done the following modification already:

1) Change all the e-cap under 100uf to Blackgate

2) Change 4 x 10000uf Nichicon Big tank to 4 x Jensen 15000uf

3) Change the default power supply 4A fuse to Furutech Green colour golden end fuse

After changed those parts, already a very great improvment althought those cap still take time run in (e.g. 100+ hrs). Sound is more musical, warm, powerful and clear now.

Problem need to be solved:

1) At the back side of OPA134P (No. C201 on the board), there is a very tiny yellow colour cap connected between 2 pin (No.4 & 7 from data sheet) under the OPA, don't know what it is used for?  If I change IC socket, still need to put this tiny cap under it?  Please see attached photo and data sheet of OPA134.  What kind of improvement can be done if I change the OPA to 627BP?

http://docs-asia.electrocomponents.com/webdocs/0028/0900766b800289f5.pdf

2) What kind of improvement can be done if change the default diode to Schotty diodle?

Existing diodle on the board:
a) A1668 -80(3 legs) x 4
b) A1477 -4B(3 legs) x 2
c) C3787 -7C(3 legs) x 2
4) 1N4002 x 4

Can recommend which diole need to be change and can be replaced by which model in Hong Kong Farnell web. http://hk.farnell.com/

3) Thare are 2 made in China relay on board (black colour) 10A (250V AC/ 24V DC), you recommend to change it?

Thanks a lot

Sugargar

the 2 small cap at pin 4&7 is connect to the ground... this cap is useful to reduce noise and some people will recommend to use 0.47uf Blackgate nx-hi-Q (as bass will be slightly better)... so i suggest you to use either 0.47NX-HI-Q or 0.47uf film cap like vishay/mkp. I also do this on my OPA and can feel the background slightly more quiet.

actually OPA134,132 and 627's sound is quite similar, but 627 is just little bit more musical....so u need to justify wheter worth to spend on this or not?? for really difference sound can try AD 825 but need socket loh as AD825 is soic.

basically schotky diode sound more smooth and analog...but the effect not so obvious compare to the change of capacitor.

for the diode, i think u shall change the 1n4002, it is rated at 100v,1A, so u can replace by shotky diode with the same or even better in higher rating. NXP, vishay also ok lah, better get TO-220 type for easier soldering.
the other 3 leg diode can temporary maintain....

for the relay, i didn't change, anyway u can try to get a compactible japanese made 1 if you want.. NEC or so on..

Thanks a lot for great information!!

I have placed the order for diode and 627BP and only need to buy Blackgate 0.47uf cap at Thursday, maybe can finish my 8000P upgrade project at this weekend. Will post test report as soon as possible.

Sugargar