Yaqin mc10L

[audionut44]

I'm not sure, just says 8ohms on the back. Musical Fidelity MC4 v1 from the late '80s

My research tells me they're around 90dB 1W/1M which is exactly the same as what I'me running so now I'm extremely interested in your impressions!

 

[Barbieboy]

My research tells me they're around 90dB 1W/1M which is exactly the same as what I'me running so now I'm extremely interested in your impressions!

Thanks for the info on the speakers

The resistors have arrived, but can't remember what I need to do. Anyone got any photos of the triode mod ?

 

[tnolan]

If you hadn't found this out there on the net to date, you should definitely have a copy handy:

http://homepage.ntlworld.com/lez/YAQIN MC10/A LOOK AT THE YAQIN MC10L.pdf

My MC-10L mutant is down currently for a 12AT7 rewire, recap and general cleanup of the front-end board. I'll let folks know how that goes.

 

[Barbieboy]

Yes did have this guide, but didn't know Les had updated it, top man !

Triode mod: Ok got the lid off, but I am crap at reading schematics..

- So how can I know which pin is what ?

- Can I snip the wires with the board still in situ ? Looks like a right pain to remove

 

[audionut44]

I would absolutely remove the board for the mod and yes it's a pain to remove. you have to remove the transformer if my memory serves.

 

[Barbieboy]

Uff not looking forward to that...

Meanwhile I replaced the preamp 1K resistors with the same Takman used on the rear. Very good and worthwhile, expanded the soundstage sideways noticeably

 

[Hi_Q]

I would tip the unit over, resting on the transformers and remove the base panel. Yep I know it is a chore with so many screws to remove but note which ones come from where.
When the base panel is removed, all the output tube holders are very accessible to do the required operations on the output transformers U/L screen grid taps etc.

 

[Barbieboy]

I would tip the unit over, resting on the transformers and remove the base panel. Yep I know it is a chore with so many screws to remove but note which ones come from where.
When the base panel is removed, all the output tube holders are very accessible to do the required operations on the output transformers U/L screen grid taps etc.

Nice one Les, far less hassle that way !

 

[audionut44]

Les is the man! Now get that mod done and let me know how it sounds! Ill need to order some more Takmans and the required components for the triode mod should I decide to do it.

 

[Barbieboy]

Les is the man! Now get that mod done and let me know how it sounds! Ill need to order some more Takmans and the required components for the triode mod should I decide to do it.

Will do it soon, just a bit scared about being able to identify the correct pins to snip

 

[Hi_Q]

Does this help?

 

[Barbieboy]

Certainly does Les ! Thanks

 

[Barbieboy]

Ok its done.

MC10L in triode mode

Pros: Sound is more 'silky' and refined with blacker background.

Cons: Less bass.

The above is with 2 hours listening, using 4x Svelana EL34 & 4x Electro Harmonics 6922 running 2-way 90db 1/watt 8ohm bi-wired speakers

 

[audionut44]

Any change in soundstage? My resistors will be here Monday.

 

[Barbieboy]

No change in soundstage, darker background allows more detail in bass guitar strings. Also bass seems to be returning, presumably due to resistors needing some burn in time. Sound overall is less fatiguing and refined are my impressions

 

[audionut44]

Cool! The sense of less bass could be a result of tighter more defined bass rather than a reduction in bass. Have you played at louder volumes? Does the amp seem to be straining at all?

 

[Barbieboy]

Yes did crack it up on my second session last night, all was fine and requires turning the knob only a little more than before. Though wish I have let the preamp Takman's burn in for longer to evaluate them properly, think they are still easing in. Odd how never noticed this on the output valve mod

 

[audionut44]

I believe my parts will be here today. I'll be giving this a go, it is reversible after all...

 

[tnolan]

I believe my parts will be here today. I'll be giving this a go, it is reversible after all...

Just remember to cut or desolder the UL wire at the pin for easiest reconnection.

 

[Barbieboy]

Just remember to cut or desolder the UL wire at the pin for easiest reconnection.

I opted for the cut, wires were too wound for an unsplattered removal.

Have a tea tray placed to the side of the upside down amp for putting all the different size screws on and so in line for easy referencing when putting the amp back together !