A probation violation hearing is different than a trial. At a trial, you have the right to a jury and the District Attorney must prove the case beyond a reasonable doubt. At a probation violation hearing, the judge hears the evidence and you are not entitled to a jury, and the prosecution only has to prove it is more likely than not that you violated probation.
The "technical/new arrest" notation may mean your probation terms required you to report all law enforcement contact to your probation officer, and you failed to do so.
You definitely need an attorney to handle this for you, especially with a suspended sentence hanging over your head. If you can't afford to hire your own, the judge will appoint one when you go to court.
The reason that your probation is being violated is because part of the terms of your probation is "to obey all laws." The probation officer who handles your case gets updates from law enforcement when you get arrested. Usually the arresting officer would contact your probation officer after he/she made the arrest and inform your probation officer, who then files the violation to see if the DA's office will file charges.
If this new arrest was the only basis for your violation, and it seems like it is from what you wrote, then the probation officer will not proceed with the violation. The probation officer usually places the hearing on calender after an arrest to see whether the DA's office will file the new charges. In this case, since the DA's office is not going to file the new charges the probation hearing should be taken off calender. If you have proof, such a letter sent from the DA's office, that no charges are going to be filed then bring the letter with you. Show that to your public defender if you don't have an attorney. If there is a probation officer present on your hearing date, the probation officer would usually ask the court to withdraw the probation violation and reinstate your probation.
In some cases, the probation officer may ask to continue the hearing for status for two weeks to make sure the DA's office did not file new charges against you.