Hi all


Hope you can support on this topic, I'm tryng to install a switching channel for the 18W TMB EF86,

I have used a relay between the TMB and EF86 channels, but I get noise when from the TMB switch to the EF86 channel, and pop sound on switching.

I have attached the schematic,

Please any suggestion are welcome

Thanks
 
 

Hi all

I'm planning to install a vvr in a 18w tmb ef86, Has anybody done it?

I have seen the Dana Hall vvr kit, but not sure what mods are required to the circuit (R and C at the inlet of the  preamp) .

Is anybody able to point to a schematic or drawing ?

thanks

Hi thanks for the useful information.

I'lo go for 2 of 16 ohm.it Is more versatile.

I have looked around on the web and I have seen the following  speakers
http://wgs4.com/catalog/british-invasion

Now here I see very different types and prices...wondering if anyone can provide some feedback and if ever been used with a 18w tmn ef86

I like British sound and I use mostly distortion..any recommendation?
Thanks

Hi all

while I wait for the new turret board , I would like to start the speaker cabinet.

Please do you have any recommendation on a good speaker suitable for the 18W tmb EF86..

Do I go for 1 or 2 x 12" cabinet?

Is any preferred speaker impedance? I'm using a mercury O18RS-FS that can accept 4-8-16 ohm.

How do i select the speaker power?
 
Suggestions are welcome
thanks

Hi
Thanks for the recommendation ... I have been testing and testing the amp, finally with surprise I discovered that the board used for the Turret , is faulty; actually it is not isolating at all. I can measure an impedance between turret while they should be insulated.
I have been discussing with the supplier and hopefully I will get a replacement soon...

Now I have to rebuild ll the turret board...life!!

Will keep you updated

Thanks

Hi all

I have finally completed to build a 18W TMB eF86, and I'm in the process of testing it ....and here we start with the problems...

I tried a shot and I notices the TMB chanel does not work at all, the EF86 sounds horrible and fade down.

I have been tested the connection several times and they looks right, but I can see some voltages that do not seems right to me.

With the tube rectifier and preamp in, all pot to zero I record an unbalanced Voltage at the two anode of the Phase inverter on the V2 - 12AX7.

V2
Pin1      162V
Pin 2      76V
Pin 3&8  80V
Pin6      239V
Pin7       70V

As the circuit is symmetrical I expect a similar voltage between Pin 1 and Pin 6

And the same for Pin 2 and Pin 7 when both channels Volume are grounded

This is the schematic I have followed
http://www.verelec.com/tijdelijk/images/Ceriatone%2018W%20TMB%20EF86.pdf

I have checked, re-soldered and replaced all the anode and cathode resistors and capacitors but nothing change, and I have tried to swap the preamp tubes.

Please some help
thanks
 

Dear Wyatt

I have looked athe the link you have provided for the transformer

on the TAD website I can see two models for the PT

http://www.tubeampdoctor.com/en/shop_Mains_transformers_Mains_Transf_for_Marshall/Mains_transf_for_Marshall_18W_Plexi_TAD_Amp_Kit_955


http://www.tubeampdoctor.com/en/shop_Mains_transformers_Mains_Transf_for_Marshall/Mains_transf_for_Marshall_18W_Plexi_US_version_3265

On the other web site

http://www.ig-transformatoren.com/catalog/en/transformers/mains-transformer/275/igmt-m18tmb?c=48

While for the OT I see the two options

http://www.ig-transformatoren.com/catalog/en/transformers/output-transformers/282/igot-m18r?c=49

http://www.tubeampdoctor.com/en/shop_Output_transformers_Output_Transf_for_Marshall/Output_transf_for_18W_Plexi_Kit_958

I can see some price difference on these, is any beeter than the other?
spec looks similar

The TAD OT has a 9.2k impedence rather than 8k

What you think?

Hi

Thanks for the reply , very helpfull.

I have seen in the schematic for the 18W TMB  the presence of a PPIMV, Is this a master volume for both chanels (TMB and normal)? Do you reccomend this ?

Another point is the bias of the output stage.
The cathod bias is used in this schematic, do you think a fixed bias is possible in this type of circuit ?

What would be the difference in sound?

I heard about the possibility to switch between fixed and cathode bias. Any reccomendation on this?

thanks

 

Following to the previous post

Using the schematic http://www.keepandshare.com/doc/2194569/ceriatone-18-watt-tmb-schematic-a-3-layout-23-59k?da=y

I have the following list 

Quantity     Name           Value
2   R1,R4                          1M
2   R2,R3                              68K
1   R5                                   22K
4   R6,R7,R13,R19   820
6      R8,R9,R11,R15,R22,R23   100K
1   R10                                   100
5   R12,R18,R20,R25,R26   470K
2   R14,R21                          56K
1   R16                              2.2K 2W
1   R17                              33K
1   R24                              8.2K 2W
2   R27,R28                      8.2K
1   R29                              130 5W
1   R30                               100 2W
1   R31                              1.5K  5W
1   R32                              100K 3W

2   C1,C2                      1uF/63V
5   C3,C7,C10,C12,C13      0.01u yellow
2   C4,C11                      0.0047u
2   C5,C9                      0.022u
1   C6                              22u/450V
1   C8                              500p
1   C14                              16U/450V
1   C15                              100U/450V
1   C16                              32U/32U
1   C17                              0.047 630V
1   C18                              0.01U/3KV

How do I choose the type of these components?

thanks

I think I will move to the TMb version ...

Thanks for the Info on the Trasformer, I will do some serach to identify a product.

Now I'm looking for parts and as I'm sourcing them I would like to select good product with excellent performance, but I would require some reccomedation

Valves: I would like to use the following

EL84 Genalex Gold Lion
12AX7 Genalex Gold Lion
EZ81 JJ

Resistor,  Pot and Cap I'm not sure what to choose for the different part of the circuit, is anybody able to point me to recomendations?

Thanks very much for the Info, very helpful

I have seen a schematic on the web for the TMB version
http://www.keepandshare.com/doc/2194569/ceriatone-18-watt-tmb-schematic-a-3-layout-23-59k?da=y

Does this match the layout for the 18W TMB presented in ceritone website?

I leave in italy, so I will try to source most of the material here.
Regarding the trasformer, is any specific model and brand you reccomend ?
Is it worth to use Mercury one? I have been loking at the Mercury web and I have seen several trasformer option for the OT and PT? Which one do you suggest?
thanks 

Hi all

I'm new to the forum, and I'm planning to build a 18W TMB EF86

I'm in the process to buy a kit from Ceriatone web site. As it is my first attempt on building an amplifier (but I'm experienced with electronics) I'm wondering if the kit comes with any documentation, building instructions, schematics for an easier construction.

Or Can you point to any guide available in the form or on the web?

In addition I'm evaluating if using the trasformers and valves provided from Ceriatone. What is your experience on this point?
Do you think make sense to try using other parts for this ? Do I get any advantage?

Thanks for the support

Vi