New build Complete: 45W, four 6V6, non-HRM

[ToneMerc]

After several 100W builds I've decided to wander off the range a bit. The criteria for this build was something that works well with a Strat and just enough wattage for strip mall restaurant gigs.

Heyboer PT-308V, hoping to see about 408-415V on the plates
Heyboer 50W Marshall-M6 steel or MCI Bassman....I'll sleep on it tonight.
Heyboer choke
AGB boards
Tubes- JJ's and a balanced Sovtek LPS
Topology- modded Skyliner and a bastard plate resistor combination, I'll call MoPlate.

Got most of the outboard wiring done.

TM

TM

[David Root]

So far, so good! OT is a tough one, it would be nice to try both and see which one you like best! I think the Mag Components Bassman is M27 or M19, not M6, so it should sound quite different when pushed.

Everyone likes those CE chassis too, I do. I try to keep two in stock as they don't make many four holers, which I prefer.

Lo-plates or Hi-plates? Lo plate V1 and hi-plate V2 might be nice.

[ToneMerc]

David, MCI has two versions, the one have is a BF type with M6 steel. Yeah, I like the CE chassis as well. If there's one thing I would change would be no OT holes. I have 4 holer, one day I might try a CF type circuit with reverb.

No high plates in this one.

TM

[David Root]

M-C seems to have been bringing out several new pieces of iron, I'll have to look over the list again.

I built a 4-6V6 earlier this year, not a Dumble but a 4-6V6 30W version of the '59 2-6V6 DeArmond R-15. I like 4-tube amps.

What's going to be on the FSW?

[ToneMerc]

What's going to be on the FSW?

It's been around awhile
http://www.classictone.net/40-18001.html

Just OD & PAB

TM

[ToneMerc]

A few more, I just about have all the perimeter wiring done.

[amplifiednation]

Merc,
Good to see this build is underway. A 35 watt version is really cool. I'm looking forward to hearing how it comes out. Looks good!

[renshen1957]

After several 100W builds I've decided to wander off the range a bit. The criteria for this build was something that works well with a Strat and just enough wattage for strip mall restaurant gigs.

Heyboer 50W Marshall-M6 steel or MCI Bassman....I'll sleep on it tonight.

TM

TM

Hi,

Just curious as to the OT primary ohms. 6,600 ohms? 5000 ohm's? 4000 ohm? 3500 ohm?

You might have more than 35 Watts you planned, another consideration.

Best Regards,

Steve

[ToneMerc]

Hi,

Just curious as to the OT primary ohms. 6,600 ohms? 5000 ohm's? 4000 ohm? 3500 ohm?


Best Regards,

Steve

3300

[renshen1957]

Hi,

Just curious as to the OT primary ohms. 6,600 ohms? 5000 ohm's? 4000 ohm? 3500 ohm?


Best Regards,

Steve

3300

Hi Tonemerc,

With 415V on the plates and OT transformer at 3300, your amp will produce 50 watts of power. With 408V on the plates, about the same 50 watts.
I based the above on Voltage saturation (80V) for a standard tube such as a 6L6.

The 6V6 tube has lower saturation (60V) drop. With 415V your output would be closer to 59 Watts. Your four 6V6 tubes dissapation will be 14.8W per tube.
These better be sturdy 6V6s JJ have maximum values at 14 Watt At this voltage a 6L6 would be a better bet or one could locate some 5992 redbank (Bendix, Tong Sol, Richardson and very expensive) tubes if your had your heart set on 6V6 tubes.

At 408V, the Power output will 57 Watts, the 6V6 will be dissapating 14.2W per tube.

In either case the difference in sound level difference between the 6L6 and the 6V6 would be negligible. Either choice would be a bit louder than the 35W design target.

Jim Kelley's FACS had 490V on the plates and a OT at 4300 for a 60W amp fueled by four 6V6. His amp had about 12 Watts on the original Sylvanias. Even then Kelley's amps (the combos) have a reputation for being hard on the 6V6 tubes (from the inherent vibration of the speakers).

All the above plate numbers are idle voltage, at full load the plate voltages will become lower. (Take my word for this, I don't recommend attempting to measure plate voltages with an amp dimed.)

If you used a 16 ohm speaker on the 8 ohm tap (or an 8ohm speaker on the 4 ohm tap) of your , the ratio of the OT would then be 6600, and circa 30 watts. The alternative is to find a custom wind prmary at 5600 ohms for the target 35watt power output.

Best Regards,

Steve

[talbany]

Wev'e built quite a few of these 4X6V amps in the HRM topology running around 460 using Marshall OP Iron and let me tell you it has far more headroom than 2 6L's..We use the JJ's as well and yes they are a tough ass tube.. I have not had 1 complaint of premature failure with them in my 4X6V amps.. Burn them in..

Good Luck TM

Tony

[jelle]

Ok, this will sound weird....The JJ 6V6 is not a 6V6.

It is a russian tube that is close to a 6V6 but also close to a 6L6, not the 6L6GC.
Strong little fellow, hard to kill.

I wonder what will happen to those amps designed around the JJ6V6 when these tubes are no longer made....

[talbany]

I wonder what will happen to those amps designed around the JJ6V6 when these tubes are no longer made....

Put in a pair of 34's or 6L's or 66's in them..Be real simple to add the option of switching between 2 different pairs of tubes on the fly..Plenty of options with this design..

Tony

[ToneMerc]

We use the JJ's as well and yes they are a tough ass tube.. I have not had 1 complaint of premature failure with them in my 4X6V amps.. Burn them in..

Good Luck TM

Tony

I concure, I've mentioned this to Tony before that as experiment when I built my MusicMan iron non-HRM that has 710V on the plates, I stuck in a pair of JJ 6V6's and ran them for at least 7 minutes or so. It's definitely a tough tube.

TM

[jelle]

I wonder what will happen to those amps designed around the JJ6V6 when these tubes are no longer made....

Put in a pair of 34's or 6L's or 66's in them..Be real simple to add the option of switching between 2 different pairs of tubes on the fly..Plenty of options with this design..

Tony

Cool idea! BTW, my comment was not about your amps.