MI60 Clone

[theleftfoot]

hey guys,

i tried to introduce myself in francais....as i sad i tried

anyway....i have an old ibanez hybrid tube amp...two el34 and one 12ax7 preamp tube....with some hybrid pices in it...

find yesterday this forum...and fall in love with the mi60!

so i decide to clone the mi60....

i will try to report my work....

to the layout...i find only this layout -->http://gilles.thebault.free.fr/MI60/sch ... iginal.pdf

is this the newest?

raffa

[Mikka]

Hi, and welcome on the PG5 forum.

I'm not the best informed guy about the MI60 amp here but I'm sure that the guys who worked on it will give you all you need.

Anyway it's a good choice if you like powerfull and Rock'n roll amps.

The MI60 is nothing else that a vintage french vue of the english tone.

[vitriol82]

Welcome raffa,

Don't be afraid, if you need support, we can do our best to help you.

The layout drawing seems to be correct but the drilling must be adapted for the components you'll use.

In this forum, we can made all transformers as we want or find équivalent in Hammond series.

Have a good trip

[charpy]

hello and welcome !

you can compare the layout with this schematic
http://www.projetg5.com/Projets/MI60/MI60_original.pdf

I don't see the rotoswitch for the master volume on the layout (replaced by a potentiometer). the original MI60s have au rotoswitch with a laaaaaarge knob)

Have you cheked if your ibanez amp have similar tension for A+ (440V). this is an important point for the MI60. don't care if it is 460 ou 420V, but It must be over 400V and below 480V)

[theleftfoot]

wow...merci beaucoup pour votre réponse...

i think that the OT will bring the requested power...i hope!

as soon as i can get my hands on my ibanez amp from the garage, i will check the hole tensions....

this is the amp that i will use for the mi60 clone --> http://fr.audiofanzine.com/combo-guitar ... IBZ-60-TE/

merci raffa

[theleftfoot]

salut les gars bonne année!

i finally start today with the mi60 project!

the NT has the follow specs:

input primary; 240VAC

heaters Secundary; 6.5 VAC
bias: 37.3 VAC
RMS without centertap; 380VAC

can i use this Transformer?

raffa

[vitriol82]

Hello Raffa, happy new year too

We need more informations about the Power transforner, you must say us the current delevery of each voltage the total power.

With this informations we could start the evaluation of the power supply and say you if you could use this transformer.

[theleftfoot]

alors...

the PT has 94 Watt...

380 VAC * 1.4 ->> 532 VDC

the current is --> 94/532 --> 176 mA

ces't correct?

raffa

[theleftfoot]

allo?

is someone in? wana go futher...

raffa

[McColson]

Hello, and for the heater ? How many current can he suplly ?

[charpy]

I think 94W is a a very minimum for a MI60 clone and your calcul is wrong. you must use AC value.

you need : 6.3x4A = 25W for the heater
and 380Vac x 0.2A for the high voltage = 76W

so your transformer may be good but you must not overload it : chose a cold biasing point and dont not use the amp into saturation at full power if the load is small (below 5k).

could you check the load of the output transformer (inject AC voltage to the plates terminals an measure the voltage at the output terminal). give us your measure I will calculate the primary load.

[theleftfoot]

okay, will do it ce soir!

[vitriol82]

Sorry for the delay,, I don't see the new messages

Generaly the power for a 50W amp is around 250VA to be comfortable, the AC current needed for the HV is around 300 / 400 mAac

After you had the power needed for the heather you must find a power around 250 VA, and for the HV voltage, you can found the informations on the thread on the forum.

[theleftfoot]

alors les gars,

je suis fini! ... and the amp works on the first launch! manific!

but got two problem!

1. the bias vollatage is okay....32.6 V but the current on the tube are 90 mA! i can't adjust more on the trimmer is full up!

what can i do? should i increase the resistor ?

2. i get a really loud buzz when i start up the baby from the standby! is that because the current is to high? the heater all okay...about 6.4 VAC

thanks for the help

btw; some pics..

[theleftfoot]

hey guys, whats up?

can someone help me out! please