Yes, I run the amp with the speaker... and the volumen was very low... The volumen problem started at this point, since I turn on the amp when I finish it...

I'm tired but I am very happy to find the problem. I already know the memory circuit from the times I have reviewed it ... Will the problem be solved by changing the OT?

A lot Thanks for your time and help!

J

Yes, it should solve the problem. But I wonder why the OT is down. The shop delivers quality OT, so there must be a reason why the OT is now as it is.
I'm just worried, that a new one gets shot again.
And no idea if the 6v6 are still ok, as I have no clue how they liked the test sessions at full blast with the steep reflected impedance.
Your 10W resistor was actually ok, as the delivered power was very low from the start. I was just worried that you used it at full blast before testing the amp with an instrument. Then you might have damaged the OT.

Also, as you checked your build several times, measured everything several times and that was ok, it seems that the OT may have been like this from the beginning. Surprising but possible, if they are not tested for function by the manufacturer (what I doubt for that one).

I would suggest you to get in touch with the shop using the standard manner (form in the website or email), explaining your issue, and the steps you went through.

Laurent

Thank you very much Laurent and Robert for your help!
I contact the store ...

Best Regards,

Jaime

Zitat von: Laurent am Mai 22, 2020, 08:05
Yes, it should solve the problem. But I wonder why the OT is down. The shop delivers quality OT, so there must be a reason why the OT is now as it is.
I'm just worried, that a new one gets shot again.

das ist genau der Punkt. Die Erfahrung zeigt, dass ein defekter Transformator in der regel nicht die Ursache sonder das sichtbare Ergebnis für einen Fehler im Aufbau ist, insbesondere wenn man bedenkt, dass die Übertrage mit 1kV oder 2kV getestet sind.
Normalerweise gehört so ein Verstärker ordentlich geprüft.

Gruß, Dirk

I am interested in enjoying the amp now and for many years. After all the checks we've done on the amp: visual, static and signal tests, we couldn't find any problems (except OT). How do you recommend that we verify the amplifier correctly, Dirk, to definitively rule out a structural mistake in the device?

Zitat von: Pringles1 am Mai 23, 2020, 05:08
How do you recommend that we verify the amplifier correctly, Dirk, to definitively rule out a structural mistake in the device?

The answer is simple: in a tecnical correct way. This includes voltages, current, oscillations (with a scope), power and heat.

Best regards, Dirk

Hahaha...
And I was nervously waiting for your answer to illuminate the doubts to enjoy the amp with my jazz bass... :guitar:
jajaja! :facepalm:

Hi,

Do not give up with the nerves.

With the remote servicing as we do here, we are at the limit of what we can do. My doubts remain concerning the very root cause of the problem with the OT. Maybe you can find a serious and capable tech in your area so that he can have a look at it ?

Anyway a new OT needs to be installed but beforehand a complete check would be safer.

We also have no clue, how you checked the amp before the first time you ran the amp with tubes. There are many steps involved to ensure safety and proper wiring in order to avoid a bad experience.
So I would strongly recommend you to find a local support as soon as the quarantine is over in Spain (or is it already?)

Laurent

Thanks Laurent, you are an angel!
I will follow your advice and tell you the final results!

Hallo,

the Amp finally arrived at our workshop, we tested it and can not find any problem. Well, one of the powertubes was slightly worn  ( maybe because of the troubleshooting ? ) so the total power with this tube was 18 Watt, with a new powertube the power is now 20 Watt which is perfect. Everything else is also fine, we can not find a problem.
I guess that you expect a much higher volume and did not check any of the parameter or the power but started to search for none-existing bugs.

Best regards, Dirk

Thanks Dirk!

Dirk, It's a good and bad news ... Good news because the amp work fine, like you say. Bad news because I continue to have a problem. I'm looking for a amp to play bass at home. I built few years ago a 5E3 amp (18w, and I can't turn up the amp volume and the guitar volumen of more than 50% without being afraid of glass breaking) and Madamp G3 (3w that I can play at home without having fear that the neighbors will call me). When I connected the BFlex (amp volume Full and bass volume Full) and the Madamp G3 (amp volume Full and bass volume Full ) to a Jensen C12N (8 ohms) and a Hartke 15 '(8 ohms), the Madamp G3 sound little louder than Bflex ... Could I expect more power from BFlex amp?

The power of the BFlex is around 20 Watts,  and this is what we measured with your amp.  I do not know what loudness you expect but the BFlex  should be loud enough for home use and also small stages.  If the amp is not loud enough for your needs than you must use an other amp. I do not know your setup and what else you use so  I find your error description difficult to categorize. I just can tell for sure that the amp works as it should.

Best regards, Dirk

Dirk, everybody know the quality and the interesting of your amp designs and the quality and seriousness of your work. I hope I can enjoy your  personal version of the 5E3 soon...
I am sure the design of the BFlex is great for playing bass and that it has to meet my needs. In that sense, I don't understand why it sounded so low at home. Hopefully the trip to Germany, the tube change and the resoldering of OT it's sound fine too. Thanks for the help, Dirk.

Hallo,

we compared the BFlex with the 5E3 and the loudnes is almost the same but the 5E3 is overdriving a lot  so if you want a clean bass sound you must lower the volume so finaly the 5E3 is not as loud as the BFlex.

Best regards, Dirk

Hi,

I'm not sure whether this has been suggested earlier but you might want to try a different speaker with a higher sensitivity.

Best, Peter