Seeing that perhaps due to costs etc, the Mullard 3 Watt is probably not worth building. So thoughts go to the Mullard 10 Watt. I would appreciate any feedback from people that have built it and if they came across any issues. I would appreciate posts only about this Mullard 10 Watt amplifier.
Thanks.
Thanks.
Why build The Mullard 10 watt amp? A much better el84 push pull amp to build, are the Tubelab Simple PP. Sounds great!
+1 for the above.
2nd to none support, great PCB, then you can invest in the generic hardware for a EL84 PP amplifier, and if you fancy something a little more esoteric you can recycle it all into a point to point amplifier.
2nd to none support, great PCB, then you can invest in the generic hardware for a EL84 PP amplifier, and if you fancy something a little more esoteric you can recycle it all into a point to point amplifier.
Thanks for that, i just thought that as Mullard Limited was a British manufacturer.....
I'll take a look at Tubelab..
I'll take a look at Tubelab..
The beauty of Tubelab is that he has a very forum on this site, where support is never far away ...
Tubelab
Many here have built one of his different offerings, a lot of people developing their skills from the PP build to the 300B (or similar) TSE build. There is an exciting new development in the pipeline to harness tubes that are not normally considered to be for audio.
Tubelab
Many here have built one of his different offerings, a lot of people developing their skills from the PP build to the 300B (or similar) TSE build. There is an exciting new development in the pipeline to harness tubes that are not normally considered to be for audio.
Just curious: if you are building the amp yourself, why does it matter where the design originated from?
FYI, the Mullard company, as it existed at the time this design was published, is long gone. The brand name lives on as part of the Electro-Harmonix line of vacuum tubes (see link below) but other than that it has no relationship with the old Mullard company.
https://www.ehx.com/tubes
The design is OK.
One gotcha is the output transformer.
Often it is rare, expen$ive, or Un-Obtainum.
Many other transformers will work, but often they may require some changes to the negative feedback compensation.
Compensation includes the global feedback parallel RC from the output transformer secondary to the input pentode cathode circuit.
And . . . compensation also includes the series RC across the pentodes plate load resistor.
Just saying.
Note:
For pentode operation, Mullard lists 2 different primary impedances.
For distributed load (also called Ultra Linear, UL), Mullard lists 2 different primary impedances, and the UL tap % is different versus the primary impedance.
Quite interesting and quite informative of Mullard.
Now, that is my comments on the amplifier just as you requested; no comments on more modern or different amplifiers.
One gotcha is the output transformer.
Often it is rare, expen$ive, or Un-Obtainum.
Many other transformers will work, but often they may require some changes to the negative feedback compensation.
Compensation includes the global feedback parallel RC from the output transformer secondary to the input pentode cathode circuit.
And . . . compensation also includes the series RC across the pentodes plate load resistor.
Just saying.
Note:
For pentode operation, Mullard lists 2 different primary impedances.
For distributed load (also called Ultra Linear, UL), Mullard lists 2 different primary impedances, and the UL tap % is different versus the primary impedance.
Quite interesting and quite informative of Mullard.
Now, that is my comments on the amplifier just as you requested; no comments on more modern or different amplifiers.
Last edited:
There is an older (and lengthy) thread on this forum dealing with building the Mullard 5-10, including transformer selection. This might be helpful.
https://www.diyaudio.com/community/threads/new-build-mullard-5-10.310062/
https://www.diyaudio.com/community/threads/new-build-mullard-5-10.310062/
We just want to help you...You can not speak to the amp, so American, English, French.... i I have build 4-5 different El84 PP and many SE amps the last 10-30 years. Tried the old things like Fischer, Scott, Mullard, Morgan Jones "Bevois valley"? amp, but it did not work for me. Sounded flat and I did not like them at all. A year ago I jumped into a Tubelab Simple PP amp, with point to point soldering. A pair of el 84 and one ecc81 on each channel, and the amp sound great. I used Hammond 1650 output transformers. I have been building tubeamps for the last 30 years, and the Tubelab are the one everyone should build! Thanks!!!
Thanks Stenak, i'll revert back to Tube labs. Being in Europe, just wondering about obtaining all the parts from the least amount of suppliers to avoid courier costs, delays etc., and the least amount of import duty.
Ideas for a case?
Last edited:
Hammond has a range of aluminium chassis that are easy to work with:
https://www.rapidonline.com/Catalogue/Search?Query=hammond aluminium chassis&Size=60
Are there a workshop in the area where you live? Make a drawing and ask the workshop how muck it costs to make a chassie? I like to build with aluminium. That because it is easy to work on, easy to drill holes in, etc. My amp chassie got aluminium with 1,5-2mm thickness. Start to make a plan over the parts you will need...capacitors, resistors, transformers, and so on. There are a lot of people out there who sells components, and many of us have to much lying around, and will sell/give away for "nothing". Where are you living? Find the right schematic on the intrnet. Look around you, use standard capacitors and resistors. Do not buy cheepish transformers, I am a fan of Hammond and use a 370HX and 1650E for output transformers, and chokes for the power supply. The chassie are 41cm x 29cm x 8cm, (w-d-h) and I think I found it near a trash-can? Probably have been a power supply, or something used in the PC-world? Just look around? Good Luck, https://www.diyaudio.com/community/threads/made-myself-a-el84-pp-tubelab-clone.381104/
Last edited:
I did use DigiKey too for the Hammond transformers, e-Bay for tubes and chassis, and Aliexpress for some other bits. DigiKey includes tax and delivery on the price quoted. Total charge for 2x 1650HA + 1x 372JX was £374 delivered.
Last edited: